Which of the following sentences contains an adjective clause?

The correct answer is Option (2) → The farmer whose tractor broke down borrowed one from his neighbour.

Adjective clause after a noun:

• An adjective clause describes the noun or pronoun just before it. It begins with a word such as who, which, whose or that.
• Here “whose tractor broke down” tells which farmer borrowed a tractor. It describes the noun “farmer”, so it is an adjective clause.

Why the Other Options are Incorrect?

Option 1: We will start the match as soon as the umpires arrive. — Incorrect. “As soon as the umpires arrive” tells when we will start. It goes with the verb “start”, so it is an adverb clause of time. Example: Call me as soon as you reach home.

Option 3: Nobody could explain why the street lights went off at nine. — Incorrect. “Why the street lights went off at nine” is the object of “explain”. It does the work of a noun, so it is a noun clause. Example: I do not know why the bus is late.

Option 4: What the shopkeeper said about the price was not true. — Incorrect. “What the shopkeeper said about the price” is the subject of “was”. It does the work of a noun, so it is a noun clause. Example: What you said made her happy.