Etimology
From Middle English coude, couthe, cuthe, from Old English cūþe, past indicative and past subjunctive form of cunnan (“to be able”) (compare related cūþ, whence English couth). The 'l' was added in the early 16th century by analogy with should and would; this was probably helped by the tendency for 'l' to be lost in those words (and so not written, leading to shudd, wode, etc).
verb
could
simple past of can
conditional of can
(obsolete except Geordie) past participle of can
Examples
Before I was blind, I could see very well.
I think he could do it if he really wanted to.
I wish I could fly!
Could I borrow your coat?
Could you proofread this email?
Even without hovering drones, a lurking assassin, a thumping score and a denouement, the real-life story of Edward Snowden, a rogue spy on the run, could be straight out of the cinema. But, as with Hollywood, the subplots and exotic locations may distract from the real message: America’s discomfort and its foes’ glee.
We could rearrange the time if you like.
You could try adding more salt to the soup.
I haven't could sleep.
Related words
related terms
can
should
would
noun
could (plural coulds)
Something that could happen, or could be the case, under different circumstances; a potentiality.
Examples
When the golf ball is there, the whole self-interference package — the hopes, worries, and fears; the thoughts on how-to and how-not-to; the woulds, the coulds, and the shoulds — is there too.
Shushona you must learn to rightfully prioritize all the woulds, shoulds and coulds of your life.