Question

That was my car.I sold it in 2012. (Combine the sentence using 'which')

Answer 1

That was my car. Which I sold it on 2012

Answer 2

That was my car which I sold in 2012. -This is the answer.

About pronouns and their usage:

• Pronouns are words that are substituted instead of a noun (name of a person/ thing/ place). They are used to avoid the repetition of nouns.
• Here we have to join both the sentences using the relative pronoun 'which'.
• Relative pronouns are pronouns that relate something to the rest of the sentence. (Eg): that, which.
• In the first sentence we have the speaker indicating a car. In the second sentence the details about that car is revealed. So we need to add 'which' after 'car' and then give the detail.
• We have to remove 'it' from the second sentence because we are already talking about the car as a single sentence.
• Therefore the answer is: That was my car which I sold in 2012.