The sentence: "Er hat Reim in seinem Gedicht benutzt."
My instructor has suggested that I rewrite the sentence using "a more sophisticated construction, such as one with 'lassen'." How would I do that?
After some hard thinking, my only guess is that he actually meant "sich reimen lassen", although this also would be very unusual. Where I come from - Germany - we would just say:
Das Gedicht reimt sich.
We also would rarely use your construction either ;) To use the word 'lassen', well, I am not entirely sure if you can use it on an entire poem, but for single words we can say
Dieses Wort lässt sich reimen.
And for the entire poem:
Sein Gedicht lässt sich reimen.
which might change the meaning of your sentence. I would probably understand, that there is something that rhymes with the poem, instead of the poem using rhymes.
You may notice, we rarely use "Reim" as substantive, we almost always use the verb. The only uses of the substantive that is used would be:
Ein Reim auf 'lesen' ist 'Besen'.
or when we have to analyse a poem, and have to note the rhyme scheme. This happens quite rarely, so you may just use "Das Gedicht reimt sich". Again, I do not know the context (and why your teacher would want you to use 'lassen').
sounds like a strange suggestion, because you would have to replace
hat benutzt with
lassen, and they dont mean the same
you could write
Er lässt Reime im Gedicht vorkommen. but how you wrote it sounds better, so better keep this, but add an