1. The train leaves at 7 this evening.

2. The train will leave at 7 this evening.

3. He meets the girl at 7 this evening.
4. He will meet the girl at 7 this evening.
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#1 means #2, right? What about #3 and #4? Does #3 mean #4? Is #3 grammatical?

All of these are right.

1 and 2 mean the same thing.

3 and 4 mean the same thing.

Yes, #1 and #2 have the same meaning. They both indicate that the train is scheduled to depart at 7 this evening.

As for #3 and #4, they have slightly different meanings. #3 implies that the person regularly meets the girl at 7 in the evening, indicating a habitual action or arrangement. On the other hand, #4 suggests a future event where the person will meet the girl at 7 this evening.

To determine if #3 is grammatical, we need to analyze it further. "He meets the girl at 7 this evening" uses the present simple tense, which typically expresses habitual or regular actions. While it might sound a little unusual, it is grammatically correct if it reflects a repeated occurrence.

In contrast, #4 uses the future simple tense with the auxiliary verb "will," indicating a future action. It is more common and straightforward to express a one-time, upcoming event using the future tense.

So, in summary, #3 and #4 do not have the same meaning. #3 suggests a habitual action while #4 refers to a specific event in the future. While #3 might sound a bit unusual, it is grammatically correct in the right context.