"When", "during", and "while" all have the same meaning, but they are used in different ways and follow different grammar rules.

We use all three of these to say that some action or event happens at the same time as another action or event.

1. During

Use "during + noun". We can use this at the beginning or end of a sentence. For example,

• During the summer, it rains a lot.
• During class, do not use your phone.
• He fell asleep during the meeting.
• She cried during the movie.

2. When

Use "when + sentence". So, you need a subject and a verb. We can use this at the beginning or in the middle of a sentence. For example,

• I stay inside when it is hot.
• She is quiet when she is angry.
• When she comes, we will eat.
• When we finish, we can go home.

3. While

Use "while + sentence". "While" is followed by a sentence just like "when". Sometimes, you can use either "while" or "when" and the meaning is the same. "While" really emphasizes that two actions or events happen at exactly the same time. For example,

• My brother studied while I watched TV.
• He snores while he sleeps.
• We drank coffee while it was raining.
• It rained while we were coming down the mountain.

To summarize, each of these has two actions or events, and both things are happening at the same time. "During", "when", and "while" have similar meanings, but it is important to know the difference.

Knowing the difference between these three similar words will help your English sound more fluent and natural.