had to用法

1 Had to表示"不得不，必须"，用于表达强制、义务或压力。 2 这种用法通常与情态动词“should”或“ought to”替换，并加上动词不定式，以避免过度使用had to。 3 比如，我们可以说“I had to study for the exam”，或者用“should have”替换为“I should have studied for the exam”...