This is a good question. I looked up some phrasal verbs to see if there were any I didn't know (there had to be!) an lo and behold, I found some. A few examples: argue down, argue out, bail up, beaver away, and big up. Without the context these were nearly impossible to guess. However something I do is take the meaning of the individual words and pair them together to create meaning. I would guess 'argue down' means to beat someone at an argument because you're a) arguing and b) going down on them, and that implies giving them a good thrashing, so I'd assume that you're winning. Turns out I'm right. 'Beaver away' is easy to guess because you just have to think what a beaver does traditionally - work hard. And that's exactly what the phrase means. Not all phrasal verbs are like this though, especially ones that have their origins outside America (at least from my experience).

Yes, guessing the meaning from context is what we normally do. We might compare the phrasal verb to other phrasal verbs to guess at its meaning as well.

usually, however the days of guessing are over, try google translate

Thank you. But i don't have any troubles with a phrasal verb.This post is just my interest.

Hi Naoki, could you give examples of phrasal verbs whose meanings you have trouble understanding?