It this his T-shirt?
No, it isn't.
これは何？と質問して (ask what the object is in English)
What's this?
What're they wearing? マスク
They're wearing masks.
What are they wearing? (ジャケット）
They're wearing jackets.
Is this his T-shirt?
Yes, it is.
Are they wearing rain boots?
No, they aren't.
これらは何？と質問して (ask what the object is in English)
What're these？
Are these his socks?
Yes, they are.
これらは何？と質問して (ask what the object is in English)
What're these?
Whose socks are these?
They're his socks.
Whose T-shirt is this?
It's his T-shirt.
Whose T-shirt is this?
It's her T-shirt.
What's he wearing?
He's wearing socks.
What's she wearing?
She's wearing a T-shirt.
これは何？と質問して (ask what the object is in English)
What's this?
Are these his slippers?
No, they aren't.
彼らは長ズボンを履いていない。（no pants)
They're not wearing pants.
Are these her slippers?
Yes, they are.
Are these her slippers?
No, they aren't.
Is this her T-shirt?
Yes, it is.
It this her T-shirt?
No, it isn't.
Whose slippers are these?
They're her slippers.