1.Thank you for visiting our nursing home. It was great fun last weekend.

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In Sentence 1, what does 'It" refer to?

2. Look at the elderly person.
3. Look at the elderly people.
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Are both OK? Is Sentence 2 grammatical? Can we use the singular noun after 'elderly'?

1. The visit.

Elderly can be used to modify both.

1. In Sentence 1, "It" refers to something that was mentioned previously, but it is unclear what that previous mention is. Without more context, it is difficult to determine what "It" is referring to. It could be referring to a specific event, experience, or activity that the speaker is referring to as "great fun" in the previous sentence.

2. Yes, Sentence 2 is grammatically correct. "Look at the elderly person" is referring to a single elderly individual.

3. Sentence 3 is also grammatically correct. "Look at the elderly people" is referring to multiple elderly individuals.

Both sentences are acceptable, but they refer to different quantities of elderly individuals. Sentence 2 refers to one elderly person, while Sentence 3 refers to multiple elderly people.

Using the singular or plural form after "elderly" depends on the specific context and the number of elderly individuals you are referring to.