When writing an essay on a specialized subject, you should use the terms appropriate to the subject but never employ jargon where simple terms would do. Any handbook discusses problems and answers other questions you might have concerning word-choice. Most spelling errors are inexcusable, especially titles and authors or works studied in the course. Use a dictionary and proofread typed essays and transcribed pages. If the expression is commonplace, discard it.
Most cliches indicate laziness and trite thought.
Shifts in tense . This scheme will produce shifts in tense which are legitimate and graceful as long as you are consistent. Pronoun reference . If they do not, repeat the proper noun or reword the sentence in some way. The vagueness of the word often betrays vagueness in the idea.