Perception Verbs + Object: Infinitive or -ing

Level B2 · Verb Patterns

see, watch, hear, notice, feel, and listen to can all take an object followed by a second verb, and the form of that second verb changes the meaning of the sentence. Object + bare infinitive describes the whole action, witnessed as one complete event from start to finish: I saw him cross the street and reach the other side safely — I watched the entire crossing. Object + -ing describes the action in progress, something the observer caught mid-way without necessarily seeing it start or finish: I saw him crossing the street, but I looked away before he got to the other side — I only saw part of it.

The pattern is perception verb + object + bare infinitive for a complete action, or perception verb + object + -ing for an action in progress:

• see/watch/notice + object + bare infinitive = the whole action, beginning to end: I watched her paint the entire picture, from the first brushstroke to the last.
• see/watch/notice + object + -ing = part of an ongoing action, not necessarily the start or the end: I watched her painting as I walked past the studio.
• hear + object + bare infinitive or -ing works the same way: I heard him play the whole song from start to finish / I heard him playing the piano as I climbed the stairs.
• feel + object + bare infinitive or -ing: I felt the ground shake and then everything went still / I felt the ground shaking beneath me as the tremor continued.
• listen to + object follows the same pattern even though it isn't a one-word perception verb: I listened to her sing the whole song from beginning to end / I listened to her singing as I walked past.
• Like make, let, and help + object + bare infinitive, this pattern drops to after the object — but here the choice between the bare infinitive and -ing carries its own meaning (complete versus in progress), which causative verbs don't have.

Two mistakes are common. The first is adding to before the infinitive: I saw him to cross the street is wrong — perception verbs take a bare infinitive after an object, not a to-infinitive: I saw him cross the street. The second is treating the infinitive and -ing as interchangeable when the meaning actually depends on the choice. If you only witnessed part of an action, -ing is required, even where the bare infinitive might otherwise sound fine. I saw him breaking into the car, but I didn't see how it started should not become I saw him break into the car, because that wrongly claims you saw the complete event, not just part of it.

Look for a perception verb (see, watch, hear, notice, feel, listen to) followed directly by an object and then either a bare verb or an -ing form. A completion marker in the rest of the sentence — reaching an endpoint, 'the whole way', 'from start to finish', 'until' something happened — signals the bare infinitive. A partial or interruption marker — 'but didn't see how it ended', 'as I walked past', 'when ... and had to look away' — signals -ing.

Practice

Complete Action or In Progress? · More Practice with Perception Verbs