Identify the part of speech of the underlined word : It will be five years before we meet again.

The correct answer is C, Conjunction. Here before joins two clauses, It will be five years and we meet again. The second clause has its own subject (we) and finite verb (meet), so before is a subordinating conjunction introducing a dependent time clause.

Why the others fail:

• Preposition (A): a preposition needs a noun or pronoun object, as in before the exam. Here the word is followed by a full clause, not a noun phrase.
• Adverb (B): an adverb modifies a verb or stands alone, as in I have seen this film before. In this sentence it links two clauses, so it cannot be an adverb.
• Adjective (D): an adjective qualifies a noun or pronoun. Before here qualifies nothing; it relates the time span to the meeting.

Core concept: function in the sentence decides the part of speech, not the word's spelling. The same word can change category, so always test what it does. This matters for Mains English and for precis writing, where misreading a connective changes the meaning.

Trap: aspirants see before and pick Preposition by habit. Check what follows it. A clause with its own subject and verb means conjunction.