First of all, “whose” is a question word which we use to ask “Who does it belong to?” or “Who do they belong to?”

Look at these examples below:

1. “Whose shoes are these?” shouted mum from the hall. = Who do these shoes belong to? = Who is the owner of these shoes? 
They are mine. I’ve just bought them in the sales.

2. Teacher: “Somebody’s phone is ringing! Whose phone is it? Could you please switch it off?
Sorry, it is mine. I was sure it was on silent.

3. Whose parents are coming to the meeting?
I know that Sophie’s mum is coming, I’m not sure about the others.

4. Whose sunglasses are these?
They are Fabio’s. I can tell because they are Gucci.

5. Whose jacket are you wearing? It’s much too big for you!
It’s Mark’s. I was too cold and he gave me his.

Secondly, we can use it in a sentence to say that something belongs to somebody.

Look at these examples below:

• I don’t know whose shoes they are.
• The person whose phone is ringing should leave the class now!
• The pupils whose parents are coming to the meeting, could you please raise your hand?
• Fabio, whose sunglasses are lying on the table, is a fashionable guy. 
• I don’t care whose jacket you are wearing, you shouldn’t borrow things from other people.

NOTE: Do not confuse “whose” with “who’s”! ”Who’s” stands for “who is” or “who has”. Compare these sentences:
Whose shoes are these? = Who do they belong to? Who is the owner of the shoes?

but

• Who’s left their shoes in the hall? (= who has left) 
• I don’t know who’s coming to the cinema tonight. (= who is)
• I have no idea who’s got the best marks for the grammar exam. (= who has)

When to use “those”?

Generally, we use “those” when we point to things and people or describe things and people which/who are far away. When we are talking only about ONE thing, we use “that”.

“This” and “these” are used to talk about things or people which are near.

Have a look at these examples:

• What’s this? It’s a lighter. (near)
• That car is Italian. (far)
• These watches are Swiss. (near)
• Those cars are far away. (far)