Understanding the Core Difference
When we use see, hear, or feel with a gerund (verb + ing), we describe witnessing an action in progress. When we use these verbs with an infinitive, we describe witnessing a complete action from start to finish.
Actions in Progress vs Complete Actions
Use gerund (-ing): I saw him running (caught him in the middle of running)
Use infinitive: I saw him run (watched the entire action from start to finish)
Use infinitive: I saw him run (watched the entire action from start to finish)
Examples
I saw the bird flying across the sky.Uses gerund because we caught the bird in the middle of its flight
I saw the bird fly into its nest.Uses infinitive because we witnessed the complete action from start to finish
I heard the children laughing in the playground.Uses gerund because the laughter was ongoing when heard
I heard the glass break when it hit the floor.Uses infinitive because it was a single, complete action
Common Mistakes to Avoid
❌ Incorrect: I saw him to run across the street.
✅ Correct: I saw him run across the street.
Explanation: Never use 'to' infinitive after see/hear/feel – use bare infinitive
❌ Incorrect: I felt the wind blows on my face.
✅ Correct: I felt the wind blowing on my face.
Explanation: Use gerund for continuous sensation, not present simple
Tips for Success
- Ask yourself: Did I witness the entire action or just catch it in progress?
- For ongoing actions or partial observations, use the gerund (-ing)
- For complete actions witnessed from start to finish, use the bare infinitive
- Remember that sensory verbs never take 'to' infinitive
Learning Path Notes
Key Concepts in This Series:
- Builds on previous understanding of gerunds and infinitives
- Focuses on specific sensory verbs and their unique grammar patterns
- Completes the pathway by addressing complex usage distinctions