请问为什么是didn't imagine,而不是haven't imagine?

请问为什么是didn't imagine,而不是haven't imagine? 为什么是it doesn't matter而不是it didn't 或haven't matter Don't Imagine This didn't haven't You can’t imagine ______. Haven't anyone corrected these books yet?这里为什么是haven't而不是has I haven't seen him for many years.I hardly imagine ___ grown we didn't expect to meet her there,so imagine our s_____ on I can't imagine me without Can't imagine the world without you.. You can’t imagine ______.选择题 I can't imagine how much homework do I need to finish.请问这个句子