Once recorded, the words become unchangeable. Sentence combining activities can help alter this attitude. Indeed, some researchers have proposed that it is not sentence combining itself that helps students write longer sentences but rather the discussion of the sentences that causes the learning to occur. This theory remains to be proved. Nevertheless, students do benefit from discussing composing.
Uncued exercises lend themselves well to sharing and comparing.
Cued exercises can easily be checked for correctness, but this probably isn't enough. Students also need to discuss how they made the combination, when such a sentence would be most effective, why a combined sentence may be better than the original pair, and what was gained and lost by combination. In essence, the resulting sentence probably should not be the end of the activity but rather the springboard to further discussion. Sentence combining is a versatile instructional tool. It comes in different forms and can be used to achieve different purposes.