How to say "I love you too" in English

A young Asian boy recently moved to America to live with his Grandma with his sister. The only problem is, his sister is fluent in English, Tobito cannot speak English but understands everything. He can't afford a tutor and his sister is never home. He is always picked on at school and he meets a young girl who helps Tobito against the rest of the school. She does not know that Tobito can understand her after everything she has "told" him.