I think friendships are the key - he needs motivation to communicate above all. What are his interests? Might be worth picking a friend for him based on the fact that they go to similar activities, place of worship or have passion for same computer game?
Phonics work all well and good but I think he needs the graduate to do ++ help with learning to play games, playground vocab, colours; if a child taps him on the shoulder and says 'You're it', what does it mean, that kind of thing. Game vocab; my turn, your turn, you've won, start, finish, back to the start, back one, miss a turn, champion, skillz, dice numbers, let's play.....sports vocab too: if he already plays some sport it might be a source of confidence as he may have the vocab there.
Our library has dual-language books in some languages - well worth ordering some of those perhaps? He could read the bit in his own language, a friend could read the English page.