A shy high school boy can also be described as introverted, timid, reticent, reserved, or bashful. These words suggest that the boy is hesitant to express himself, may feel uncomfortable in social situations, or is uneasy around unfamiliar people. On the other hand, a more positive alternative to "shy" may be "quiet". This suggests that the boy is thoughtful and contemplative, rather than lacking social skills. Alternatively, "gentle" may be used to describe a boy who is kind and considerate, but perhaps a little hesitant to assert himself. Ultimately, the precise word chosen will depend on the reader's intended meaning and the tone of the piece.