As you may know, the Japanese language contains a veritable hoard of loan words, many of which are borrowed from English. For us native Englisher speakers and for those Japanese studying our language, this is a mixed blessing.This is because a lot of these loan words have undergone some kind of metamorphosis and either their meaning or form has changed slightly (though sometimes this is also due to a discrepancy in the English language itself between countries).
For example: パンツ (pantsu) and "pants." Pants meaning "pants" would be nice, but...
When we Americans hear pants, we think of something like this:
However, Japanese people, when they hear パンツ, tend to think of something like this (yeah, sorry, that is a weird picture of underwear):
On more than one occasion I've lazily used パンツ in conversation with my girlfriend when I wanted to say "pants." I think she knows what I mean by now, but it's a bad habit I've gotten into. The Japanese word for pants (or slacks) is actually ズボン, which comes from French. I always get it mixed up with soft-shelled turtle...(すっぽん).
Ok, maybe not the best example since "pants" means something different depending on whether you use American or British English, I guess.
I also mentioned that some loan words change their form. The best example I can think of is the word "challenge." In English, you can overcome a challenge, or you can challenge someone to a duel, or challenge yourself to do something, etc.
In Japanese, though, we have チャレンジする, which actually means "try." As a result, you have people (including Japanese English teachers) challenging things. Sometimes when I would ask my students a question, my Japanese partner would try to encourage them by telling them (in English) to challenge my question. While this makes total sense in Japanese (質問をチャレンジしてね - "Try to answer the question"), in English it either sounds like the student should be challenging me, or else it just doesn't make sense.
There are also a lot of Japanese phrases that are cobbled together from English words and don't really make any sense to us native speakers. A few examples are:
マイペース ("my pace"), which means at one's own pace or doing things at one's own time or schedule.
エコ ("eco"), which means (and is an abbreviation of) "ecological." Lately in English we say "green."
キャバ ("Cyaba"), which is kind of a shortened form of "cabaret" and means just that.
エヌジー ("NG"), used mainly in texting and on the internet, from the English "No good" and meaning the same. A native English speaker could probably figure this out by context, but it's not natural usage as far as I'm aware.
リフォーム ("reform"), usually meaning "renovation."
This "Japanese English" is the downside to having a language that borrows many words from English. Love it or hate it, though, it is what it is.
As a Japanese learning English or an English speaker learning Japanese, has this pattern made learning difficult or frustrating for you? Or has it helped you in some way? I'm curious to know!