never
从不，从来没有;一点也不
- I swear I would never cheat on you.
我发誓我决不会欺骗你。
2.I will never tell anyone about our secret.
我永远不会告诉任何人我们的秘密。
3.Never give up what you are doing.
永远不要放弃你正在做的事情。
4.I would never do anything to hurt him
我决不会做任何伤害他的事情。
never ever
从不，永不(比never语气更强)
1.I will never ever believe you.
我永远都不会相信你。
2.I will never ever eat spicy food.
我将永远不会吃辛辣的食物。
3.I never ever want to see you again.
我再也不想见到你了。
4.I will never ever do it again.
我尽不会再犯异常的过失了。
have never done
从未做过(从过去到目前都没有，以后不一定)
1.I have never seen so pretty girl.
我从未见过这么漂亮的女孩。（现在见到了）
2.I have never been to BeiJing
我从未去过北京。
3.My parents has never taken the plane.
我父母从未坐过飞机。
4.I have never been so scared in all my life
我一生中从来没有这么害怕过。
I have never seen such a shameless person。
我从未见过如此厚颜无耻之人
