My curriculum teaches blends like -ng, -mp, and -nk separately, but they aren't ever USED separately, as far as I can tell.
So, I introduce them and then mention that they aren't found by themselves. I quickly proceed to -ing, -ong, -ink, -onk, -amp, etc. and ALWAYS mention them with a vowel, never alone, and form word families. (My former class had trouble with these, until I did this.)
The same goes for -ff and -ss. It seems crazy to teach these without vowels, so I don't.
