guarantee的用法

1、如：I guarantee to pay off his debts. 我保证还清他的债务。guarantee sb. sth =guarantee sth to sb. 向某人保证某事

3、如：The art dealer guaranteed the picture genuine.那个画商保证这幅画是真的guarantee that+句子

4、如：I guarantee that she will come 我保证她会来。