aux.v.
Past tense of will2 - Used to express desire or intent: She said she would meet us at the corner.
- Used to express a wish. This sense is archaic ( “I would you were so honest a man!” —William Shakespeare) except in contexts with an implicit first person singular subject and followed by a clause beginning with that : Would that it stop snowing!
- Used after a statement of desire, request, or advice: I wish you would stay.
- Used to make a polite request: Would you go with me?
- Used in the main clause of a conditional statement to express a possibility or likelihood: If I had enough money, I would buy a car. We would have gone to the beach, had the weather been good. See Usage Note at if.
- Used to express presumption or expectation: That would be Steve at the door.
- Used to indicate uncertainty: He would seem to be getting better.
- Used to express repeated or habitual action in the past: Every morning we would walk in the garden.
Usage Note: If the president would have informed his advisers, the scandal could have been avoided. If the economy didn't improve, the governor never would've won the election. You won't find sentences like these in well-edited prose. What you will find is: If the president had informed his advisers, the scandal could have been avoided. If the economy hadn't improved, the governor never would have won the election. Although constructions using would have instead of had or did plus an infinitive instead of had and a past participle are common in informal speech ( If you would've told me you were leaving, I could've gone with you ), they are generally not considered correct in formal writing. But why not? Many conditional ( if…then ) constructions seem bewilderingly picky about which tenses, moods, and auxiliaries may go into them, particularly those that have to do with a counterfactual or make-believe world—one that the writer thinks is likely to be false but whose implications are worth exploring. But the grammatical requirements are actually quite straightforward: 1. The if -clause must have a verb in the conditional subjunctive mood (which many linguists call by the Latin name irrealis to distinguish it from the ordinary English subjunctive). When referring to situations in the present, this mood is identical to the preterite or past-tense form ( If you danced better… ) except for the verb be, whose irrealis is were rather than was ( If he were rich… ). When a writer wants to refer to a situation that hypothetically could have occurred in the past, a more remote past form must be used—the past tense of the preterite, also known as the past perfect or the pluperfect ( If you had danced better…; If he had been rich… ). 2. The then -clause must contain would or a similar modal auxiliary such as could, should, or might. A large percentage of the Usage Panel disapproves of past counterfactual constructions using did rather than had : in 2011, 74 percent disliked If I didn't have my seatbelt on, I'd be dead, and 89 percent found it unacceptable to say If he didn't come to America, our team never would have won the championship. Panelists found forms using would have somewhat more acceptable: the sentence If she would have only listened to me, this would never have happened was acceptable to 46 percent of the Panel. This represents quite a change from the 1995 ballot, in which the same sentence garnered an acceptability percentage of just 14 percent.