How to say "to have ever" and "to have never" in Chinese?
For example

1. I've been to Thailand.
2. I've never been to Thailand.
3. I've eaten Italian food before.
4. I've never eaten Italian food before.
5. I've done this.
6. I've never done it before

Question

How to say "to have ever" and "to have never" in Chinese?
For example

1. I've been to Thailand.
2. I've never been to Thailand.
3. I've eaten Italian food before.
4. I've never eaten Italian food before.
5. I've done this.
6. I've never done it before

Answer

verb + 过 expresses past experience
没（有） +verb + 过 have not done 
从来没（不）+ verb + 过
1. 我去过泰国. I've been to Thailand. 
2. 我从来没去过泰国. I've never been to Thailand. 
3. 我以前吃过意大利菜. I've eaten Italian food before. 
4. 我以前从来没吃过意大利食物. I've never eaten Italian food before.
5. 我以前(曾) 做过这件事. I've done this before (once) 
6 我以前从未做过这件事（从未+verb +过）can replace 从来没

Answer

“ to have ever ” 是 （曾经）去、吃、做……过 的意思。
“ to have never ” 是 从未去、吃、做……过 的意思。

Answer

1. I've been to Thailand.
我去過泰國
2. I've never been to Thailand.
我沒有去過泰國 is "I haven't been to Thailand"
我從來沒有去過泰國 is "I have never been to Thailand"
3. I've eaten Italian food before.
我吃過意大利菜
4. I've never eaten Italian food before.
我沒有吃過意大利菜 is “I haven't eaten Italian food"
我從來沒有吃過意大利菜 is ”I have never eaten Italian food"
5. I've done this.
我做過（這個）
6. I've never done it before
我沒有做過（這個） is "I haven't done this"
我從來沒有做過（這個） is "I have never done this

從來 is ever, 從來沒有 is never. You can change this to 從未, which is more formal and seen in written Chinese.

Laurence