1.在情态动词must,can(could),may(might),ought to,shall(should),will(would）后例如：He could be here soon
2.在不定式to后It's a great honour to be invited to Mary's birthday party.
哪种情况会直接使用be的原型?
1.在情态动词must,can(could),may(might),ought to,shall(should),will(would）后例如：He could be here soon
2.在不定式to后It's a great honour to be invited to Mary's birthday party.