Definition of "could" [could]

• Used to indicate ability or permission in the past: I could run faster then. Only men could go to the club in those days. (auxiliary-verb)
• Used with hypothetical or conditional force: If we could help, we would. (auxiliary-verb)
• Used to indicate tentativeness or politeness: I could be wrong. Could you come over here? (auxiliary-verb)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "I don't know if I could get you a gig there, but if I *could* would you want to?"
• "I used to always wonder why I could be so awful to my family my parents, my sister, and I think it's because I knew I *could* be so mean to them & they would always be there."
• "This means that when we speak of a person's actions, in most cases he could have done otherwise, given the Stoics 'analysis of ˜could™ and other modal concepts."