Understand that the speech therapist would introduce one sound at a time -- in the office (showing them how to form their lips/tongue), then at home you can work with them for 20to30 minutes every day for a week. You would then go back and try a new sound.
So, if he can't say the ?f?, ?chi?, or 'y' correctly, have him repeat the sound in words with that initial/middle/& ending sound like cheese/marching/catch. Have pictures (or dictionary) with the words printed so that they see and identify them.
And get little prizes of the bubble gum etc to reward them for working hard. Kids get frustrated or bored with practicing.
He should have been going to speech therapy
already by this time.