Episode 52: I Saw Him Leave

see/hear/watch + inf vs -ing — Moon landing viewers, 1969 (B1-B2)

Grammar Box

Meaning: Perception verbs (see, hear, watch) take bare infinitive for complete actions or -ing for actions in progress.

Form: see/hear/watch + object + bare infinitive (complete) OR + -ing (ongoing)

Example 1: I saw him land on the moon. (complete action, witnessed from start to finish)

Example 2: I saw him walking on the moon. (action in progress, ongoing at that moment)

Common mistake: Wrong: I saw him to land. Better: I saw him land. (no “to” after perception verbs)

The Challenge

Luna tried to describe a concert: “I watched her to sing,” then “I watched her singing,” then “I watched her sing.” Which was right? All three felt different. The watch pulsed with the glow of distant Earth. Professor Wisdom appeared, holding an old television. “Witnessing,” he said, “is about what we see and how we see it. Complete or ongoing. The whole event or a frozen moment. Let me show you when 600 million people watched the same thing at the same time.”

The Journey

July 20, 1969. Around the world, families gathered around televisions. Grainy black-and-white images from 240,000 miles away. The Apollo 11 lunar module had landed hours ago. Now everyone waited, watching the hatch. What they were about to witness would be described in different ways, each revealing a different grammatical relationship to the moment.

In Houston, Mission Control watched Neil Armstrong descend the ladder. Engineers saw him step onto the surface. Complete action. Start to finish. “We saw him land,” they would later say. “We saw him plant the flag.” Each infinitive captured a completed event they witnessed in its entirety.

But in homes across America, families had been watching Armstrong moving on the moon for minutes, mesmerized by the slow-motion bouncing, the careful movements in reduced gravity. “I watched him walking,” one child told her diary. “I heard him talking to Earth.” The -ing form captured the ongoing nature of what they observed — not just the moment of landing, but the continuous, surreal experience of watching a human being exist on another world.

In Moscow, Soviet scientists watched too, silently. They had lost the space race. One engineer wrote in his journal: “We heard the Americans celebrating. We saw them succeeding where we had failed.” The infinitives made the actions feel final, complete, irreversible.

But on the moon itself, Armstrong looked back at Earth and saw it rising over the lunar horizon. He watched it hanging in the black sky. He heard nothing but his own breathing in the suit. These -ing forms captured duration, the ongoing nature of being present in that alien landscape. Not just witnessing a moment, but living inside it.

The difference mattered. “I saw him land” means you witnessed the landing event. “I saw him landing” means you observed the process, perhaps joining midway. Both are correct. Both are true. But they describe different relationships to the same history.

The Deep Dive

Perception verbs (see, hear, watch, feel, notice) can take two forms after the object. The bare infinitive describes a complete action witnessed from beginning to end: “I saw the whole concert” becomes “I saw her perform” (the entire performance). The -ing form describes an action in progress or ongoing: “I saw part of it” becomes “I saw her performing” (action already in progress when I observed).

The meaning difference is subtle but important. “I heard him leave” suggests I perceived the entire departure process. “I heard him leaving” suggests I caught him in the act of departing — perhaps heard the door closing or footsteps fading. With “watch,” the -ing form often emphasizes duration: “I watched the sunset” (complete) versus “I was watching it setting” (ongoing process).

These verbs never take “to” before the infinitive in active voice. “I saw him to go” is wrong. However, in passive voice, “to” returns: “He was seen to leave” (not “He was seen leave”). Understanding this distinction helps create precise, natural descriptions of witnessed events.

More Examples

History: Millions watched the Berlin Wall fall and saw people climbing over it, dancing, embracing freedom.

Science: Researchers observed the chemical reaction and saw the color change instantly when the substances mixed.

Everyday: Last night I heard my neighbors arguing loudly, and this morning I saw them leaving together, apparently reconciled.

Formal: Security cameras watched the suspect enter the building at 9:15 PM and recorded him leaving at 10:47 PM.

Informal: I was watching TV when I heard something crash in the kitchen — turned out my cat was jumping on the counter.

Contrast: “I saw him cross the street” (complete crossing) vs “I saw him crossing” (caught him midway) — different temporal relationships.

Practice & Reflection

Exercises:

Fill in the blank: In 1969, millions _ Armstrong _ on the moon and _ him _ across the surface. (saw / step / watched / walk)
Correct the mistake: I heard her to sing at the concert last night.
Choose and explain: Which suggests you witnessed the entire action?
a) I saw him leaving.
b) I saw him leave.
Rewrite: Use a perception verb + -ing: “I observed the process of the sun setting.” → “__”
Compare: “I watched her dance” versus “I watched her dancing” — which emphasizes ongoing process?
Your reflection: Describe something you witnessed recently. Use one complete action (bare infinitive) and one ongoing action (-ing).

Answer Key:

saw / step / watched / walking (or walk) — infinitive for complete moment; -ing emphasizes ongoing movement
I heard her sing — no “to” after perception verbs
b) leave — bare infinitive = complete action witnessed; -ing = in progress
I watched the sun setting — -ing form emphasizes the ongoing process
Second (-ing form) — emphasizes duration and ongoing nature
Check: bare infinitive for complete action, -ing for ongoing/in-progress?

The Lesson

Luna wrote confidently: “I watched her perform the entire song. I saw her singing with such emotion.” Both correct, both capturing different aspects of the same moment. The watch dimmed. She thought about those millions watching the moon landing — some seeing the complete event, others watching the ongoing miracle of human beings existing where they shouldn’t. Grammar doesn’t just describe what happened. It describes our relationship to what happened. Whether we witnessed the moment or lived inside it. The difference between seeing history and watching it unfold.