As far as I know, the words' roots in Esperanto come from non-constructed languages (this is what Wikipedia says about it).
As I speak English, Russian and some French and know a bit of Latin, I very often can guess the meaning of words because they resemble their English/Russian/French/Latin equivalents (or at least relatives).
The problem is with the verb farti (to be / to feel), especially in sentences like Kiel vi fartas? (How are you doing? / How do you do?). Mi pardonpetas, but I can't sorta unhook 'farti' in Esperanto from 'to fart' in English.
As for the similarities in other languages I know, the only one can be found in French, but it's not so similar, to my mind:
faire (fr., to do) <-> farti (esp.)
I'm constantly thinking of the wrong translation when encountering 'farti' in texts, so the questions are: where does 'farti' come from?