Building Brighter Futures
At US World Tutor, the mission is to support students as they grow into confident, capable, and independent learners. By focusing on the whole student — not just the grades — US World Tutor creates a foundation for long-term success. This is a place where students are seen, heard, and empowered to reach for their dreams.
Turn Challenges Into Triumphs
Every student faces obstacles — but no one has to face them alone. US World Tutor is built on the belief that with the right support, any learner can overcome difficulties and shine. Whether a student is struggling to keep up or looking to excel even further, the tutoring approach is designed to unlock personal strengths. These services empower students to take control of their learning and build the tools they’ll need for life.
Academic Grade 3rd - 7th
Personalized support strengthens core skills and builds confidence for future academic challenges. Focused guidance fosters effective study habits.
Test Prep Grades 3rd - 12th
Targeted preparation improves test performance through strategy and content mastery. Personalized sessions ensure readiness.
Academic Grade 8th - 12th
Tailored instruction enhances subject mastery and prepares students for advanced coursework. Support encourages independent learning skills.
A Mentor With a Mission
For John DeMartin, teaching isn’t a job — it’s a calling born from both heart and experience. From classrooms in Boston to São Paulo and private tutoring across the U.S., John has devoted over 30 years to helping students unlock their full potential. His sessions are more than lessons; they’re powerful moments of connection, curiosity, and confidence-building. Discover how working with John can inspire a lifelong love of learning in your child.
Where the Magic Happens
Breakthroughs don’t happen by chance — they happen when insight, experience, and genuine care come together. That’s the heart of what John DeMartin brings to every session at US World Tutor. Take a closer look at the moments that make all the difference.
Lessons That Stick
Teaching with clarity, purpose, and care so students truly understand — not just memorize — concepts.
Built for You
Every session is personalized to your child’s strengths, challenges, pace, and way of learning best.
More Than Grades
Helping students grow confidence, motivation, and self-awareness alongside academic success and skill mastery.
Joy Meets Mastery
Igniting curiosity and creativity so students feel excited, capable, and proud of what they achieve.
Testimonials
You are the very best! Thank you so much for all your help, support and kindness. I am beyond proud of her but I know she could have never done it without you! You were so patient with her, listening to her stories and letting her tell you the many complicated ways she gets to an answer and then guiding her back to the task at hand. You brought out the very best in her when she didn’t really believe in her abilities. We will always be thankful for you.
Cannot recommend enough. He was very patient and made sure to get to know our child as a person first and then began lessons in a way that worked specifically for our child. Could not have had a more positive experience.
Knowledge tutor while working online - John has been helping my daughter prepare to take the SSAT. She has been working with him by video conference. I did have some initial concerns with tutoring online as opposed to in person as I was unsure if it would be productive. John has made the online experience very easy by using a whiteboard app where my daughter can see his written work on math problems. My daughter has taken an SSAT practice test since working with John and her score has improved on the sections he has been reviewing with her. Tutoring online with John has been very productive and convenient during this time of social distancing.
Great tutor! Very friendly! John has been helping my son since August. He always comes well prepared to do something new with vocabulary, reading, and science. Brings his own books and materials, suggests strategies and proposals. My son is excited and as parents we see progress and motivation. John esta ayudando a mi hijo desde Agosto. El siempre viene bien preparado para hacer cosa nuevas como vocabulario, reading, y ciencias. Trae sus propios libros y materiales, sugiere estrategias y propuestas. Mi hijo esta entusiasmado y como padres vemos progreso y motivacion.
Great tutor - I hired John to tutor my 10 year old son for his upcoming standardized tests. From the first meeting, he was able to connect with my son and help him grasp concepts he didn't understand before. He does it in a manner that's relaxed but focused. After each session, my son feels he "learned a lot", comes out feeling upbeat and looks forward to the next session with him. I think we've found the right tutor. UPDATE: My son took his standardized test and did significantly better than in his practice tests in most areas. John was not just instrumental in getting him ready for it, but he went above and beyond by offering to write a letter of recommendation for one of the schools we are applying to, where he is an instructor. He also offered to introduce him to other kids that play chess at the school, this being one of my son’s interests. In addition, he was flexible in arranging times to meet with us and was a pleasure to work with. John really cares about his students. He will do whatever is in his power to make sure kids learn and succeed. He is a true teacher and I recommend him without reservation.
He helped my daughter for her SSAT - He was excellent and patient, my daughter felt so confident to present her exam. She liked the classes so much and he was always on time. His tips were very useful for the exam.
Excellent tutor - John has done an excellent job preparing my son for the math and quantitative reasoning sections of the upper school ISEE exam. John identified gaps in my son's knowledge and areas where he needed more practice. The lessons were focused primarily on helping my son build his problem solving skills in those areas. John also helped my son improve his test taking speed. My son enjoyed working with him. I recommend him highly.
John is awesome! - I was immediately impressed with John’s ability to clearly explain principles and concepts with enthusiasm and patience. John reaches a child on their individual level enabling the child to trust and embrace the skills John teaches them. John's focus is not solely on increasing grade point average but strives for the child’s broadened success in all aspects of their lives. Perseverance, hard work, dedication and seeking assistance when necessary are life lessons which once learned and applied result in personal growth and success across the board!
Amazing tutor!!! - John tutored my son for his ISEE test. He was incredibly patient with him, who tends to space off and was able to get him to concentrate on the material that was being explained. John was also very fair when it came to scheduling tutoring sessions. He was very truthful in the amount of hours that my child needed and did not try to "sell" me more hours. I would definitely seek John's services, should the need arise! Thank you, John. You were great!!! John ayudo a mi hijo a prepararse par el examen de ISEE. Fue increiblemente paciente con el, siendo mi hijo uno de esos ninos que se desconcentra muy rápido y logro ensenarle todas las materias necesarias. También me gusto mucho el hecho que no trato de venderme mas horas de las que mi hijo necesitaba. Si necesitásemos mas ayuda tutorial, definitivamente contactaría a John de nuevo. Mil gracias, John!
Knowledgeable and patient tutor - John is a great tutor: arrived on time, very understanding, arrived prepared, very knowledgeable of all the material, really loves teaching math, got us on track, helps us complete the task at hand. Thank you so much!
Amazing and knowledgeable tutor-John tutors my son for the SSAT and he has provided him with incredibly valuable advice that helped my son get a great score on his first try at the exam after only four lessons. It is clear that John is seasoned and over the years has been able to customize his tutoring sessions to the individual needs of the child. He quickly identifies your child's weak areas and focuses on strengthening them in an efficient manner, resulting in quick results and higher scores. I highly recommend John as a tutor.
Top Tutor in every category - John was great from the very first lesson. My son needed a tutor that could help him excel in the upcoming ISEE test for middle school. We only had two weeks before his test - so John gave him a crash course - non stop -in all subjects. I also appreciate that he follows through with the parents even after the session ends, so we know how it is going and what our son needs to work on. Our ISEE and SSAT tests will end soon - but we hope to continue with John throughout the year. Superstar Tutor!
You are the very best! Thank you so much for all your help, support and kindness. I am beyond proud of her but I know she could have never done it without you! You were so patient with her, listening to her stories and letting her tell you the many complicated ways she gets to an answer and then guiding her back to the task at hand. You brought out the very best in her when she didn’t really believe in her abilities. We will always be thankful for you.
Cannot recommend enough. He was very patient and made sure to get to know our child as a person first and then began lessons in a way that worked specifically for our child. Could not have had a more positive experience.
Knowledge tutor while working online - John has been helping my daughter prepare to take the SSAT. She has been working with him by video conference. I did have some initial concerns with tutoring online as opposed to in person as I was unsure if it would be productive. John has made the online experience very easy by using a whiteboard app where my daughter can see his written work on math problems. My daughter has taken an SSAT practice test since working with John and her score has improved on the sections he has been reviewing with her. Tutoring online with John has been very productive and convenient during this time of social distancing.
Great tutor! Very friendly! John has been helping my son since August. He always comes well prepared to do something new with vocabulary, reading, and science. Brings his own books and materials, suggests strategies and proposals. My son is excited and as parents we see progress and motivation. John esta ayudando a mi hijo desde Agosto. El siempre viene bien preparado para hacer cosa nuevas como vocabulario, reading, y ciencias. Trae sus propios libros y materiales, sugiere estrategias y propuestas. Mi hijo esta entusiasmado y como padres vemos progreso y motivacion.
Great tutor - I hired John to tutor my 10 year old son for his upcoming standardized tests. From the first meeting, he was able to connect with my son and help him grasp concepts he didn't understand before. He does it in a manner that's relaxed but focused. After each session, my son feels he "learned a lot", comes out feeling upbeat and looks forward to the next session with him. I think we've found the right tutor. UPDATE: My son took his standardized test and did significantly better than in his practice tests in most areas. John was not just instrumental in getting him ready for it, but he went above and beyond by offering to write a letter of recommendation for one of the schools we are applying to, where he is an instructor. He also offered to introduce him to other kids that play chess at the school, this being one of my son’s interests. In addition, he was flexible in arranging times to meet with us and was a pleasure to work with. John really cares about his students. He will do whatever is in his power to make sure kids learn and succeed. He is a true teacher and I recommend him without reservation.
He helped my daughter for her SSAT - He was excellent and patient, my daughter felt so confident to present her exam. She liked the classes so much and he was always on time. His tips were very useful for the exam.
Excellent tutor - John has done an excellent job preparing my son for the math and quantitative reasoning sections of the upper school ISEE exam. John identified gaps in my son's knowledge and areas where he needed more practice. The lessons were focused primarily on helping my son build his problem solving skills in those areas. John also helped my son improve his test taking speed. My son enjoyed working with him. I recommend him highly.
John is awesome! - I was immediately impressed with John’s ability to clearly explain principles and concepts with enthusiasm and patience. John reaches a child on their individual level enabling the child to trust and embrace the skills John teaches them. John's focus is not solely on increasing grade point average but strives for the child’s broadened success in all aspects of their lives. Perseverance, hard work, dedication and seeking assistance when necessary are life lessons which once learned and applied result in personal growth and success across the board!
Amazing tutor!!! - John tutored my son for his ISEE test. He was incredibly patient with him, who tends to space off and was able to get him to concentrate on the material that was being explained. John was also very fair when it came to scheduling tutoring sessions. He was very truthful in the amount of hours that my child needed and did not try to "sell" me more hours. I would definitely seek John's services, should the need arise! Thank you, John. You were great!!! John ayudo a mi hijo a prepararse par el examen de ISEE. Fue increiblemente paciente con el, siendo mi hijo uno de esos ninos que se desconcentra muy rápido y logro ensenarle todas las materias necesarias. También me gusto mucho el hecho que no trato de venderme mas horas de las que mi hijo necesitaba. Si necesitásemos mas ayuda tutorial, definitivamente contactaría a John de nuevo. Mil gracias, John!
Knowledgeable and patient tutor - John is a great tutor: arrived on time, very understanding, arrived prepared, very knowledgeable of all the material, really loves teaching math, got us on track, helps us complete the task at hand. Thank you so much!
Amazing and knowledgeable tutor-John tutors my son for the SSAT and he has provided him with incredibly valuable advice that helped my son get a great score on his first try at the exam after only four lessons. It is clear that John is seasoned and over the years has been able to customize his tutoring sessions to the individual needs of the child. He quickly identifies your child's weak areas and focuses on strengthening them in an efficient manner, resulting in quick results and higher scores. I highly recommend John as a tutor.
Top Tutor in every category - John was great from the very first lesson. My son needed a tutor that could help him excel in the upcoming ISEE test for middle school. We only had two weeks before his test - so John gave him a crash course - non stop -in all subjects. I also appreciate that he follows through with the parents even after the session ends, so we know how it is going and what our son needs to work on. Our ISEE and SSAT tests will end soon - but we hope to continue with John throughout the year. Superstar Tutor!
You are the very best! Thank you so much for all your help, support and kindness. I am beyond proud of her but I know she could have never done it without you! You were so patient with her, listening to her stories and letting her tell you the many complicated ways she gets to an answer and then guiding her back to the task at hand. You brought out the very best in her when she didn’t really believe in her abilities. We will always be thankful for you.
Cannot recommend enough. He was very patient and made sure to get to know our child as a person first and then began lessons in a way that worked specifically for our child. Could not have had a more positive experience.
Knowledge tutor while working online - John has been helping my daughter prepare to take the SSAT. She has been working with him by video conference. I did have some initial concerns with tutoring online as opposed to in person as I was unsure if it would be productive. John has made the online experience very easy by using a whiteboard app where my daughter can see his written work on math problems. My daughter has taken an SSAT practice test since working with John and her score has improved on the sections he has been reviewing with her. Tutoring online with John has been very productive and convenient during this time of social distancing.
Great tutor! Very friendly! John has been helping my son since August. He always comes well prepared to do something new with vocabulary, reading, and science. Brings his own books and materials, suggests strategies and proposals. My son is excited and as parents we see progress and motivation. John esta ayudando a mi hijo desde Agosto. El siempre viene bien preparado para hacer cosa nuevas como vocabulario, reading, y ciencias. Trae sus propios libros y materiales, sugiere estrategias y propuestas. Mi hijo esta entusiasmado y como padres vemos progreso y motivacion.
Great tutor - I hired John to tutor my 10 year old son for his upcoming standardized tests. From the first meeting, he was able to connect with my son and help him grasp concepts he didn't understand before. He does it in a manner that's relaxed but focused. After each session, my son feels he "learned a lot", comes out feeling upbeat and looks forward to the next session with him. I think we've found the right tutor. UPDATE: My son took his standardized test and did significantly better than in his practice tests in most areas. John was not just instrumental in getting him ready for it, but he went above and beyond by offering to write a letter of recommendation for one of the schools we are applying to, where he is an instructor. He also offered to introduce him to other kids that play chess at the school, this being one of my son’s interests. In addition, he was flexible in arranging times to meet with us and was a pleasure to work with. John really cares about his students. He will do whatever is in his power to make sure kids learn and succeed. He is a true teacher and I recommend him without reservation.
He helped my daughter for her SSAT - He was excellent and patient, my daughter felt so confident to present her exam. She liked the classes so much and he was always on time. His tips were very useful for the exam.
Excellent tutor - John has done an excellent job preparing my son for the math and quantitative reasoning sections of the upper school ISEE exam. John identified gaps in my son's knowledge and areas where he needed more practice. The lessons were focused primarily on helping my son build his problem solving skills in those areas. John also helped my son improve his test taking speed. My son enjoyed working with him. I recommend him highly.
John is awesome! - I was immediately impressed with John’s ability to clearly explain principles and concepts with enthusiasm and patience. John reaches a child on their individual level enabling the child to trust and embrace the skills John teaches them. John's focus is not solely on increasing grade point average but strives for the child’s broadened success in all aspects of their lives. Perseverance, hard work, dedication and seeking assistance when necessary are life lessons which once learned and applied result in personal growth and success across the board!
Amazing tutor!!! - John tutored my son for his ISEE test. He was incredibly patient with him, who tends to space off and was able to get him to concentrate on the material that was being explained. John was also very fair when it came to scheduling tutoring sessions. He was very truthful in the amount of hours that my child needed and did not try to "sell" me more hours. I would definitely seek John's services, should the need arise! Thank you, John. You were great!!! John ayudo a mi hijo a prepararse par el examen de ISEE. Fue increiblemente paciente con el, siendo mi hijo uno de esos ninos que se desconcentra muy rápido y logro ensenarle todas las materias necesarias. También me gusto mucho el hecho que no trato de venderme mas horas de las que mi hijo necesitaba. Si necesitásemos mas ayuda tutorial, definitivamente contactaría a John de nuevo. Mil gracias, John!
Knowledgeable and patient tutor - John is a great tutor: arrived on time, very understanding, arrived prepared, very knowledgeable of all the material, really loves teaching math, got us on track, helps us complete the task at hand. Thank you so much!
Amazing and knowledgeable tutor-John tutors my son for the SSAT and he has provided him with incredibly valuable advice that helped my son get a great score on his first try at the exam after only four lessons. It is clear that John is seasoned and over the years has been able to customize his tutoring sessions to the individual needs of the child. He quickly identifies your child's weak areas and focuses on strengthening them in an efficient manner, resulting in quick results and higher scores. I highly recommend John as a tutor.
Top Tutor in every category - John was great from the very first lesson. My son needed a tutor that could help him excel in the upcoming ISEE test for middle school. We only had two weeks before his test - so John gave him a crash course - non stop -in all subjects. I also appreciate that he follows through with the parents even after the session ends, so we know how it is going and what our son needs to work on. Our ISEE and SSAT tests will end soon - but we hope to continue with John throughout the year. Superstar Tutor!