1 (in the 2nd and 3rd persons, and often in the 1st: see SHOULD). a in reported speech (he said he would be home by evening). b to express the conditional mood (they would have been killed if they had gone).
2 to express habitual action (would wait for her every evening).
3 to express a question or polite request (would they like it?; would you come in, please?).
4 to express probability (I guess she would be over fifty by now).
5 (foll. by that + clause) literary to express a wish (would that you were here).
6 to express consent (they would not help).
Phrases and idioms:
would-be often derog. desiring or aspiring to be (a would-be politician).
Etymology: OE wolde, past of wyllan: see WILL(1)
Useful english dictionary. 2012.