While slang may be acceptable in casual speaking situations, it is not appropriate in formal writing. Colloquial language such as clichés, figures of speech, and idioms should also be avoided in academic writing.

Examples: 

*Slang and colloquial language are italicized.

 

Incorrect: At the end of the day, justice needs to be done.

Correct: Ultimately, justice needs to be done.

 

Incorrect: Some countries adopt an-eye-for-an-eye politics.

Correct: Some countries adopt retaliation politics.

 

Incorrect: The conclusion of the paper is clear as crystal: physical activity should be promoted more to kids.

Correct: The conclusion of the paper is clear: physical activity should be promoted more to children. (Example adapted from Osmond, 2016).

 

Reference

Osmond, A. (2016). Academic Writing and Grammar for Students. (2^nd ed.). London: SAGE.