Sabay is the best learner’s site, because at the top of each article is a switch for adding spaces to the Khmer, very handy for separating words!

this site has some examples of translated KM-EN sentences at the bottom

don’t forget to install myVocabu if you want to translate any Khmer into your language (select Khmer text in page and press whichever Hotkey you set up in myVocabu settings – I prefer SHIFT key for this)