Conjunctions

A conjunction joins two parts of a sentence. The exam checks that you use the right partner and only one of them.

1. Correlative pairs. They come as fixed couples: either…or, neither…nor, not only…but also, both…and, whether…or, such…that, so…that, scarcely…when, hardly…when, no sooner…than. Never mix pairs (neither…or is wrong).
2. Parallel structure after a correlative. Whatever follows the first half must match what follows the second: "He is not only a writer but also a teacher" — noun with noun, verb with verb.
3. Subordinating conjunctions of contrast and cause. although / though / even though set up a contrast; because / since / as give a cause; so / therefore give a result.
4. Special ones. unless already means "if not", so it never takes another "not"; lest is followed by "should"; until is about time, unless about condition.

The single most common mistake, and it is unmistakably a Marathi and Hindi carry-over, is doubling the connective: "Although he was tired, but he worked", "Because it rained, so we stayed indoors". In Marathi जरी…तरी and कारण…म्हणून are correct as pairs. English allows only one connective for one joint — keep the subordinator and delete the second word: "Although he was tired, he worked."

How to spot it: after writing the sentence, count the joining words between the two clauses. If there are two, one of them must go.

Fixed pairs: either–or, neither–nor, not only–but also, no sooner–than, hardly–when, so–that · one joint takes ONE connective: "Although … , he worked" (no but), "Because … , we stayed" (no so) · unless already means if-not

Spot the error: "Although he had studied hard, but he could not clear the prelims." → The clause already opens with "Although", so "but" is a second connective for the same joint. Correct: "Although he had studied hard, he could not clear the prelims." Sanity check: either connective alone works — you may also write "He had studied hard, but he could not clear the prelims." What you may never do is use both.