Hear, see etc + object + infinitive without to

Most verbs of perception (e.g. hear, see, watch, notice) are followed by object + infinitive (without to).

  • I heard him cry. (NOT I heard him to cry.)
  • I watched them play. (NOT I watched them to play.)
  • I saw her cross the road. (NOT I saw her to cross the road.)

Most of these verbs can also be followed by –ing forms. Note that there is usually a difference of meaning. We use infinitive forms after these verbs to say that we hear or see the whole of an action or event. On the other hand, -ing forms suggest that we see or hear an action in progress.


  • I once heard him give a talk on international politics. (I heard the whole talk.)
  • As I walked past his cabin, I heard him talking with his secretary. (I didn’t hear the whole talk.)

An –ing form is not usually used to refer to a momentary action or event.

  • I saw the bomb explode. (NOT I saw the bomb exploding. The action mentioned here (explosion) doesn’t last for more than a few moments.)

Sometimes an –ing form can suggest repetition.

  • I saw the children throwing stones at the dogs. (= The children kept throwing stones.)

After can see and can hear, only the –ing form can be used.

  • I could see him climbing up the tree. (NOT I could see him climb up the tree.)