In these sentences as is really used as a relative pronoun, connecting these adjective clauses to the words which they modify. As may also be used as an adverb. I am as tall as you are.

Here the first as modifies tall and is used as an adverb; the second as is a conjunction connecting the subordinate clause you are, with the principal clause. Note that in making comparisons, as is always used when the comparison is equal, so when it is unequal, thus:

We have found that as is also used as a conjunction to introduce an adverb clause. For example:

The clause, as she is good, is an adverb clause, modifying the adjective beautiful. In the sentence, Do as I say, as I say is an adverb clause of manner, modifying the verb do.

CONNECTIVE WORDS

379. Let us not be confused in this matter of connectives. There are just four classes of connective words:

  1. Copulative verbs.
  2. Relative pronouns.
  3. Prepositions.
  4. Conjunctions.