Problem: I’m working with a 4yrs old. who substitutes a “l” for “t’ and “th” e.g he will say “le” for “the”, “male” for “matter”, but it is not consistent across all word positions and words. What would you suggest?
Since he does use /l/, although inconsistently, I would recommend writing a list of /l/ words for him to practice. Practice these words daily. You can add to the list whenever another mispronounced words comes up.