The house ______ roof is yellow is my grandparents' (relative clause, of which VS whose)

Question

The house ______ roof is yellow is my grandparents'

I'm studying relative cluase of English and wondering what is the correct answer for that particular question.

At first I thought it would be of which because then the original sentences would be:

1. The house is my grandparents'
2. Roof of the house is yellow. 

But I realised that the sentence #2 lacks the proper article, the, so I think the answer might be whose. However, as of my knowledge whose is for people (or animals at best) and it is rarely used for things or objects.

So which one should be the answer? Or it is possible that the both are okay and natural? I want it to be grammatically correct but I'd also like to know which one is more 'natural'. Thanks!

Answer 1

The house whose roof is yellow is my grandparents'.

Whose is used for people, but it is also the possessive case of which (used for objects).

Since we're using possessive cases, the formulation of the answer is

The house is my grandparents'.

The house has a yellow roof.

where the roof belongs to the house.

Now, you would write accordingly:

The house that has a yellow roof is my grandparents'.

The house which has a yellow roof is my grandparents'.

Of which doesn't work because of can't be placed anywhere else in the sentence. An example of of which used correctly:

The computers of which there are few are at the back of the store.

The computers which there are few of are at the back of the store.

---

As mentioned in the comments, whose can be used for both people and things, and if you believe otherwise, you will make mistakes in the future by using the wrong possessive.

If you're looking for something more natural, your best bet is:

The house with the yellow roof belongs to my grandparents.