who
pronoun

Phrases
-
as who should say
- archaic as if to say: he meekly bowed to him, as who should say ‘Proceed’
-
who am I (or are you, is he, etc.) to do something
- what right or authority do I (or you, he, etc.) have to do something: who am I to object?
-
who goes there?
- see go1.

Origin:
Old English hwā, of Germanic origin; related to Dutch wie and German wer

1 A continuing debate in English usage is the question of when to use who and when to use whom. According to formal grammar, who forms the subjective case and so should be used in subject position in a sentence, as in who decided this? The form whom, on the other hand, forms the objective case and so should be used in object position in a sentence, as in whom do you think we should support?; to whom do you wish to speak? Although there are some speakers who still use who and whom according to the rules of formal grammar as stated here, there are many more who rarely use whom at all; its use has retreated steadily and is now largely restricted to formal contexts. The normal practice in modern English is to use who instead of whom (and, where applicable, to put the preposition at the end of the sentence): who do you wish to speak to?; who do you think we should support? Such uses are today broadly accepted in standard English.2 On the use of who and that in relative clauses see that (usage).