@AmberFatima You're very welcome! The best way of getting the syntax of a seventeen-year-old learner correct would probably be talking to someone who has taught ESL in Japan. (Perhaps the occasional confusion between base form of a verb and third person singular present "he show that the city is unsafe", and an unwillingness to use contractions?)
The education system in Japan is very exam oriented with little chance for students to use their spoken English, so a student might have an advanced vocabulary but be shy about using a lot of it. Play with it, and see how it fits your character.