Is it ok to repeat same vocabulary many times?

[Coverpool]

<p>For example, I used 9 "instruction"s in 600 word essay and 4 "instructor"s</p>

<p>Is this ok? or shall I change it to something like advise or direct</p>

[anewbeginning]

<p>Depends on the essay, I recommend you to change atleast some of them if not all.</p>