1. How about going to see a movie?
2. Why don't we go to see a movie?
3. Why not go to see a movie?
4. Shall we go to see a movie?
5. What do you say to seeing a movie?
6. Let's go to see a movie.
7. Why don't you go to see a movie?
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Are they all grammatical and the same? Are they all interchangable?
All are correct.
1 - 6 mean approximately the same thing.
7 is a bit different; the speaker could be including him/herself or not. It's not clear.
All of the sentences you provided are grammatically correct and convey the same general meaning of suggesting or proposing to go and watch a movie. However, there are slight differences in formality and emphasis that can affect their usage and interchangeability. Let's break them down:
1. "How about going to see a movie?" - This is a suggestion in the form of a question. It implies an open-ended invitation and seeks agreement or opinion.
2. "Why don't we go to see a movie?" - This is a suggestion phrased as a question. It implies a desire for joint participation and may seek a specific reason for not going.
3. "Why not go to see a movie?" - This is a straightforward suggestion. It implies that going to see a movie is a logical or enjoyable option and asks for reasons against it.
4. "Shall we go to see a movie?" - This is a polite suggestion using the modal verb "shall." It implies a proposal and seeks agreement or acceptance.
5. "What do you say to seeing a movie?" - This is an inquiry asking for a response or opinion about going to see a movie. It is more conversational in tone.
6. "Let's go to see a movie." - This is a direct invitation, indicating a desire for joint action. It is more assertive and implies a suggestion with enthusiasm.
7. "Why don't you go to see a movie?" - This is a suggestion directed at another person, implying that they should go and watch a movie. It may suggest that the speaker is unable or unwilling to accompany them.
While these sentences share similar meanings, the choice of which one to use depends on the context, the level of formality, personal preferences, and the relationship between the speakers.