Who "would" hide your cap in the tree?

English as a Second Language English Vocabulary, Grammar and Idioms
1

Nora: Hey, Harry! What are you doing? It’s dangerous up there.
Harry: Um…I’m looking for my cap. It’s somewhere up here.
Sally: Who would hide your cap in the tree?

In the above dialog, what does “would” mean?

2

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Hypothetical past tense of ‘will’, I think.
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3

Can Sally say “Who will hide your cap in the tree”?

4

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Not normally, though I suppose it’s possible. It would not be hypothetical, though. The use I have mentioned above is for ‘would’, not ‘will’.
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