This worksheet gets students thinking about when they should use the words should could or would in a sentence. I would suggest going over when we use each word with the students before starting it. For example, you could explain that "would" and "could" are the past tenses of "will" and "can" and that we usually use "should" when we are talking about something we are supposed to (or "should") do.
This could also be used as a supplement to a phonics lesson on the ou sound that the words share.
9 fill-in-the-blank style sentences.