1. While I was washing the dishes, he watched TV.

2. While I washed the dishes, he watched TV.
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(Which one is right? Are both OK? What is the difference in meaning between the two sentences?)

3. He was playing games when I called him this morning.

4. He played games when I called him this morning.
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(Which one is correct? What is the difference in meaning between 3 and 4?)

1 and 2 mean the same thing. Both are correct.

3 and 4 are similar, but 4 implies that he paid no attention when he was called.

Both sentences in question 1 are grammatically correct, and both convey the same basic meaning. The difference lies in the emphasis.

In sentence 1, the first part "While I was washing the dishes" emphasizes the ongoing action of washing the dishes. The second part "he watched TV" is a simple past tense action that happened simultaneously with the ongoing action.

In sentence 2, the first part "While I washed the dishes" presents the action of washing the dishes as a completed event. The second part "he watched TV" is also a simple past tense action that happened simultaneously.

As for question 2, both sentences are grammatically correct, but they convey different meanings.

In sentence 3, "He was playing games when I called him this morning" indicates that the person was already engaged in the action of playing games when the call was made. It suggests that the action was ongoing or in progress at the time.

In sentence 4, "He played games when I called him this morning" suggests that the person started playing games after the call was made. It indicates a simple past tense action that happened after the call.

So, the appropriate choice depends on the intended meaning and the context of the situation.

Both sentences in each set are grammatically correct and can be used interchangeably depending on the intended meaning.

1. While I was washing the dishes, he watched TV.
2. While I washed the dishes, he watched TV.

The difference in meaning between these two sentences lies in the verb tenses used.

In sentence 1 (While I was washing the dishes, he watched TV), we use the past continuous tense for the action of washing the dishes (I was washing). This tense is used to describe an ongoing or continuous action that was happening in the past. The simple past tense is used for the action of watching TV (he watched).

In sentence 2 (While I washed the dishes, he watched TV), we use the simple past tense for both actions (I washed and he watched). This tense is used to describe a completed action that occurred in the past.

The choice between the past continuous tense and the simple past tense depends on how you want to convey the relationship between the two actions in terms of their duration or completion.

3. He was playing games when I called him this morning.
4. He played games when I called him this morning.

In this case, sentence 3 (He was playing games when I called him this morning) uses the past continuous tense for the action of playing games (he was playing). This tense is used to describe an ongoing or continuous action that was happening in the past. It implies that the action of playing games was already in progress when the speaker made the call.

Sentence 4 (He played games when I called him this morning) uses the simple past tense for the action of playing games (he played). This tense is used to describe a completed action that occurred in the past. It implies that the action of playing games took place after the call was made.

Again, the choice between the past continuous tense and the simple past tense depends on how you want to convey the relationship between the timing of the call and the action of playing games.