Definition of how can/could
1
—used to show that one thinks that someone has done or said something shocking or wrong
- "We don't need his help anyway." "How can you say that?!"
- How could she just walk away from her children like that?
2
—used to express doubt that something will happen, is possible, etc.
- How could I (ever/possibly) leave this job?
- How can I (ever/possibly) thank you?
3
informal
—used to show disappointment in someone's actions, thoughts, words, etc.
- He threw away my gift? Oh, how could he?
