would

The story

1. Proto-Indo-European*welh₁-
2. Proto-Germanic*wiljaną
3. Proto-West Germanic*willjan
4. Old Englishwillan
5. Old Englishwolde
6. English todaywould

From Old English wolde, past tense of willan, predecessor of will. The loss of /l/ in this word is probably due to weak stress, as in should and could (though in the latter, the /l/ was due to the analogy of the former two).

First known use, by meaning

• from 9th c. Used to form the "anterior future", or "future in the past", indicating a futurity relative to a past time.
• from 9th c. Used to, did repeatedly, habitually; indicates an action that happened several times in the past (cannot describe continuous states, as in I used to live in London)
• from 18th c. Was or were determined to; indicating someone's insistence upon doing something.
• from 9th c. Wanted to.
• from 9th c. Used with ellipsis of the infinitive verb, or postponement to a relative clause, in various senses.
• 9th–19th c. Wished, desired (something).
• from 9th c. Used as the auxiliary of the simple conditional modality, indicating a state or action that is conditional on another.
• from 9th c. Suggesting conditionality or potentiality in order to express a sense of politeness, tentativeness, indirectness, hesitancy, uncertainty, etc.