Who’s is a contraction for Who + is.
Whose is used before a noun to ask about ownership or possession.
Notice how the second question word comes in front of a noun, picture. It is asking for information about that noun. Specifically, it is asking who the picture belongs to or who is the picture of.
We can ask other similar questions about the same picture:
- Whose phone is that?
- Whose beard is that?
- Whose hand is that?
The phone, the beard, and the hand all belong to Van Gogh.
- It’s Van Gogh’s phone. (It’s his phone.)
- It’s Van Gogh’s beard. (It’s his beard.)
- It’s Van Gogh’s hand. (It’s his hand.)
Let’s try another.
A: Whose birthday is it?
B: It’s the girl’s birthday. It’s her birthday.
A: Whose painting is that?
B:It’s Michelangelo’s painting on the Sistine Chapel ceiling. It’s his masterpiece.
I hope this helps.
If you want to learn more about Who’s and Whose, read Part 1 on the PELA blog!