cynthia20056
I can say for certain that...三楼错误。三楼写的 I can firmly/definitely/surely tell you that ...意思是,“我肯定能告诉你”,跟“我可以肯定地说”意思是不一样的!二楼语法错误。四楼用词别扭。倒是一楼的还算不错。:)
头头的奋斗
肯定 adj. affirmative, certain, definite, suren. affirmation, certainty, affirmativev. confirm, affirm, be certain, be sure
甜甜起司wasabi
比较口语化的有:Definitely!当然!I'm sure!(我)很肯定;当然Sure!当然Certainly!当然!I'm quite sure...我很肯定...Comfirm 意思是确认,比较正式的,比较官方,多用于军事,政治方面