PRONOUNS, RELATIVE AND INTERROGATIVE. What; semi-transition, how checkedWhat, being simply the neuter of the interrogative who, ought consistently to be similarly used. As, therefore, who is used relatively, we may expect what to be used so likewise. And so it is; but, inasmuch as the adjective which very early took the force of the relative pronoun, what was supplanted by which, and is rarely used relatively. Even when it is thus used, it generally stands before its antecedent (like the transitional use of who above), thereby indicating its interrogative force, though the position of the verb is altered to suit a statement instead of a question.
So Rich. II. i. 1. 87.
“What our contempt doth often hurl from us
We wish it ours again.
“What you have spoke it may be so perchance.
“It is true that what is settled by custom, though it be not
“Look, what I speak, my life shall prove it true.
good, yet at least it is fit.” B. E. 99 An unemphatic antecedent precedes what in
I cannot remember any instance where what has for its antecedent a noun, as in the modern vulgarism, "The man what said." In
“And I do fearfully believe 'tis done
What we so feared he had a charge to do.
What depends on a verb of speech, implied either in "assail your ears" or in "story," i.e. "let us tell you what we have seen," or "our story describing what we have seen." The antecedent was mostly omitted:
“And let us once again assail your ears,
That are so fortified against our story,
What we have two nights seen.
This use is common now, but we could not say
“What is done (that) cannot be undone.
The following is a curious use of what:
“To have his pomp and all what (that which) state compounds.
: i.e. "(that) with which."
“That Julius Cæsar was a famous man:
With what his valour did enrich his wit
He did set down to make his valour live.