Because it is a Dictionary and not a 'translation application' it is best to search ONE WORD at a time. Don't search sentences or phrases.
Search the basic versions of the word, usually in the present tense (such as, search 'run' instead of the past tense 'ran').
The website offers far more, remarkable data for every word when you search while logged in (such as example sentences, etymology, etc.). Try it out, register for free. It takes 30 seconds.