Correct use of some conjunctions

As

As is a conjunction. We use it before a clause, and before an expression beginning with a preposition.

·         He did as he was told.

·         He fought as a tiger does.

·         Nobody knows her as I do.

·         In 1939, as in 1914, everybody seemed to want war.

In informal English like is often used as a conjunction instead of as. This is very common in American English. It is not generally considered correct in a formal style.

·         Nobody knows her like I do.

As in the sense of though

·         Though he was young, he fought valiantly.

·         Young as he was, he fought valiantly.

·         Though the elephant was strong, it could not face the swift leopard.

·         Strong as the elephant was, it could not face the swift leopard.

So as

This structure is used to talk about purpose.

·         We went early so as to get a good seat.

·         He climbed up a tree so as to get a good view of the procession.

Such as

We use such as with a noun to introduce examples.

·         My doctor told me to avoid fatty foods such as bacon or hamburgers.

·         I have bought many fireworks such as rockets.