What are the most common preposition errors in English, like 'discuss about' and 'comprises of'?

In one line

Prepositions show relationships of time, place and direction, and many verbs, nouns and adjectives take a fixed preposition (or none), which is a frequent source of errors.

Explained simply

We say 'interested in', 'good at', 'married to', and we 'discuss a topic' (not 'discuss about'). There is no logic you can derive; you learn them like phone numbers of friends.

Technically, prepositions link a noun or pronoun to another word in the sentence. Common error types in CAT/TOEFL-level tests are: wrong preposition, unnecessary preposition, missing preposition, and confusion in time/place prepositions.

How it works

1. Time: at 5 p.m., on Monday / 15 August, in July / 2026 / the morning; since a point in time (since 2020), for a period (for three years).
2. Place: at a point (at the gate), in an enclosed space (in the lab), on a surface (on the table).
3. No preposition needed: discuss the issue, comprise three parts, reach the station, enter the room, request a refund, attend the lecture, order food.
4. Fixed prepositions: senior to, superior to, prefer X to Y, different from, congratulate on, accuse of, consist of, depend on, listen to, interested in, capable of, comply with, aware of, good at.
5. Learn in phrases and check a dictionary's example sentences.

Quick example

Correct the errors: 'We discussed about the project since three hours. The report comprises of five chapters and he is senior than me.' Correct: 'We discussed the project for three hours. The report comprises five chapters (or consists of five chapters), and he is senior to me.'

Common mistakes

• Adding prepositions after verbs that do not need them ('discuss about', 'reach to', 'request for' as a verb).
• Using 'since' for a period of time ('since two years') instead of 'for two years'.
• Using 'than' with senior/junior/superior/prefer instead of 'to'.

How MU asks it

Asked in error-spotting sets and fill-in-the-blank MCQs (1 mark each). Rewrite the full corrected sentence, and learn the fixed-preposition list and the 'no preposition' verbs, which are the most tested items.