Question

1. A doctor is a person who is trying for sick people.

2. If it snows tomorrow, I will play a snowball fight with my friends.
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Q1: Are both grammatical?
Q2: Can we use 'play' instead of 'have' as in #2?

Answer 1

No, neither is correct. A doctor is trying WHAT for sick people? And we would say "have," not "play a snowball fight."