There is a big map ____ the wall.
- A. in
- B. on(correct answer)
- C. at
- D. under
Why: A wall is a surface, and the map is touching it, so the preposition is on. "In the wall" would put the map inside the bricks, which is a different picture.
A112 questions · Beginner · Prepositions
Multiple-choice practice on in, on and at for both places and times, on under, behind, in front of, next to, between and near, on the fixed phrases at home, at work and at school, and on the time words that take no preposition. Every question is followed by the answer and an explanation.

1.There is a big map ____ the wall.
Why: A wall is a surface, and the map is touching it, so the preposition is on. "In the wall" would put the map inside the bricks, which is a different picture.
2.My parents are ____ until six o'clock.
Why: Work, home and school are treated as points and take at with no article: at work, at home, at school. "In the office" is possible, but it names the building rather than the idea of being at work.
3.We usually visit my grandparents ____ Saturday morning.
Why: On its own, "in the morning" is right — but as soon as a day is attached, the day wins and the phrase takes on: on Saturday morning, on Monday evening.
in, on and at for places and for times, the words under, behind, in front of, next to, between and near, and the time words that take no preposition at all.
The seven object pronouns, how they differ from subject pronouns, and the two positions they fill: after a verb and after a preposition.
There is with singular and uncountable nouns, there are with plurals, negatives, questions, short answers, and why the verb agrees with what follows it.