1. They will hold a party for their teacher's birthday.

2. They will hold a party for the sake of their teacher's birthday.

3. They will hold a party to celebrate their teacher's birthday.

4. They will hold a party for the purpose of celebrating their teacher's birthday.

5. They will hold a party on their teacher's birthday.
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Would you look at the sentences? Which ones are similar to #1 in meaning?

All have the same basic meaning, but two are quite wordy.

1, 3, and 5 are the best.

To determine which sentences are similar in meaning to sentence #1, let's analyze each sentence:

1. They will hold a party for their teacher's birthday.

2. They will hold a party for the sake of their teacher's birthday.

3. They will hold a party to celebrate their teacher's birthday.

4. They will hold a party for the purpose of celebrating their teacher's birthday.

5. They will hold a party on their teacher's birthday.

Sentences 1, 3, and 5 are similar in meaning because they all convey the idea that the party is being held in honor of the teacher's birthday.

Sentence 2 also conveys a similar meaning, but the use of "for the sake of" slightly alters the nuance. It suggests that the party might not necessarily be solely for the purpose of celebrating the birthday, but could also serve other purposes related to the teacher.

Sentence 4 essentially conveys the same meaning, but the inclusion of "for the purpose of" adds a level of formality or specificity to the reason for holding the party.

So, sentences 1, 3, and 5 are the ones that are most similar in meaning to sentence #1.