The multiple oppositions approach is evidence-based practice for unintelligible children who substitute one phoneme for several others! Parent-friendly directions for use are along the top, so they can be used in therapy and/or sent home for practice.
These worksheets are for children who substitute /m/ for several other phonemes. The first worksheet targets the collapse of /g,t,sh,b/ to /m/ and the second worksheet targets the collapse of /h,k,s,r,b/ to /m/. :)