肯定无疑英语怎么说

"肯定无疑"可以说成"without a doubt"或"undoubtedly"。
"Without a doubt" 源自英语中的"without + a + doubt"，意思是没有疑问。
例句：
"Without a doubt, he's the best candidate for the job." (毫无疑问，他是这个工作最佳人选。)
"I'm going to win this race, without a doubt." (我肯定会赢得这场比赛。)
"Undoubtedly" 源自英语中的"un- + doubt + -ly"，意思是毫无疑问。
例句：
"Undoubtedly, he's the smartest person in the room." (毫无疑问，他是屋子里最聪明的人。)
"The new iPhone is undoubtedly the best phone on the market." (新款 iPhone 毫无疑问是市场上最好的手机。)