He had the strong impression that someone was watching him.

他强烈地感觉到有人在监视他。

《牛津词典》

I had an eerie feeling that someone was watching me.

我当时有一种非常奇怪的感觉，老觉得有人在一直盯著我。

youdao

I had an uneasy feeling that someone was watching me.

有人在盯着我看，我感到很不自在。

youdao

Had she known someone was watching her, I'm sure she would have eaten differently.

NPR: Excerpt: 'The End Of Overeating

Not someone who was there watching while you were being damaged and he wasn't helping.

CNN: Horror of South Africa's 'corrective rape'

It never upset me because even if former coach Sven-Goran Eriksson was at one of our games, I presumed he was watching someone else and towards the end I never got the feeling he would pick me.

BBC: SPORT | Football | Kevin Nolan column