1. Where are they planning to visit on June 23?

2. What are they planning to visit on June 23?

3. What place are they planning to visit on June 23?

4. Which are they planning to visit on June 23?

5. Which place are they planning to visit on June 23?

-They are planning to visit Evergreen Nursing Home.
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Which questions are grammatical and commonly used?

In 1, I'd use "go" instead of "visit."

2 seems OK.

3 seems OK, but somewhat clumsy.

4 and 5 are OK if more than one place has been named in the preceding sentence.

All five questions are grammatically correct and commonly used. However, they differ in the specific information they are seeking. Let's break down the different aspects of each question:

1. "Where are they planning to visit on June 23?" - This question asks for the location where the visit is planned.
2. "What are they planning to visit on June 23?" - This question asks for the specific thing or activity they plan to visit or do.
3. "What place are they planning to visit on June 23?" - This question also asks for the specific location or place they plan to visit.
4. "Which are they planning to visit on June 23?" - This question asks for a selection or choice of options that they are planning to visit.
5. "Which place are they planning to visit on June 23?" - Similar to question 3, this question seeks information about the specific location or place they intend to visit.

In all of these questions, the provided answer is "Evergreen Nursing Home," which directly answers the inquiries.