1. He was surprised she came at all.

2. He was surprised that she came at all.
3. He was surprised because she came at all.
4. He was surprised when she came at all.
5. He was surprised she came after all.
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Q1: Does #1 mean #2? Are they all grammatical?

Q2: What is the meaning of 'at all' in each sentence?

Q3: What about Sentence 5? Does 'after all' mean the same as 'at all' here?

They are all grammatical. "at all" implies that she might not have come. It really is not necessary to the meaning of the sentence, but implies that there may have been a reason for her not to attend. "after all" more clearly implies that she may have had some reason not to attend or come (to the event). It's left to the imagination, but perhaps a quarrel with the host, or previous statements that she would not like to come to the event.

Q1: Yes, sentence #1 means the same thing as sentence #2. Both sentences are grammatically correct.

Q2: The phrase 'at all' in each of these sentences serves as an emphasis or intensifier. It adds a stronger sense of surprise or disbelief to the statement.

In sentence #1-4, 'at all' is used after the verb 'came' to emphasize the unexpectedness of the action. The speaker was surprised or shocked that the person came (even in the slightest way).

In sentence #5, 'after all' functions in a slightly different way. Here, 'after all' means "in spite of everything" or "despite expectations." It implies that the speaker had doubts or expectations that the person would not come, but they were surprised to discover that they did come.

Q3: Although both 'after all' and 'at all' involve the word 'all,' they have slightly different meanings. In sentence #5, 'after all' does not mean the same as 'at all.' 'After all' conveys a sense of contrast or contradiction, suggesting that something unexpected happened despite prior beliefs or expectations. On the other hand, 'at all' simply emphasizes the element of surprise or disbelief.