* tch as in "catch," "watch," "scratch"
* dge as in "edge," "hedge," "judge"
* sch as in "school," "schism," "schooner"
* scr as in "scramble," "scream," "screw"
* str as in "street," "strong," "strap"
There are also some trigraphs that are less common, such as:
* ght as in "night," "light," "might"
* tch as in "stitch," "fetch," "ditch" (different sound than the "tch" above)
Let me know if you'd like more examples, or if you have any other word puzzle questions!