The verb of perception (see, watch, notice, hear, listen, feel) are followed by bare infinitive or by -ing form (present participle).
If we want to say that we heard or saw the whole action from beginning to end, we usually use bare infinitive
E.g. I saw him sign the cheque.
If we want to say that we only saw or heard part of the action, we use -ing form
E.g. I saw the consultant waiting in reception.
(I saw the consultant. He was waiting in reception.)
Fill in the gaps with the infinitive (Without “to” ) or the -ing form of the verbs in brackets.
1.Did you hear those dogs __________ (bark) most of the night?
2.I noticed him __________ (throw) a sweet wrapper on the floor, so I asked him to pick it up.
3.I was able to watch them __________ (build) the new car park from my office window.
4.I watched him __________ (climb) through the window, and then I called the police.
5.I heard the baby __________ (cry) for most of the night.
6.When you came out of the station, did you notice the children __________ (play) musical instruments across the street?
7.Vicky heard someone __________ (close) the door.
8.We found Matthew __________ (exercise) in the gym.
9.She saw a man __________ (lie) in the street.
10.He heard the bomb __________ (explode).
11.I saw a woman __________ (cry). She was in a terrible state.