English shares no linguistic relationship with Japanese.
- The grammar is different.
- The sentence structure is different.
- The writing system is very different.
So, it is with a breath of relief for the native English speaker to discover the world of katakana words--most of which are based on English vocabulary.
But--hold your 馬 (uma - horse(s)).
Just because it looks like English and (sometimes) sounds like English doesn't mean that it means the same thing as in English.
When a foreign word is imported into any language, it becomes a part of that language and culture. This means, the meaning and usage of words often change from its original meaning.
Before we get started, let's learn what these words are called in Japanese.
wasei eigo literally means "Japanese created English" and refers to words that were created by Japanese and reworked to mean something somewhat different from the English word(s) they were based. An example is ブラインドタッチ which is literally a combination of "blind" and "touch." This means to type on a keyboard without looking at the keys--touch typing.
gairaigo literally means "foreign words" and it equivalent to "loanword." These words were not created in Japan, but like waseigo, the meaning may have been modified. Other than Chinese, the earliest 外来語 were from the Portuguese. During the Meiji Period, German and French were popular. In the 20th century and continuing today, the bulk of modern loanwords come from English.
Here are a dozen words that probably don't mean what you think they mean.
English Cousin: Viking
Explanation: Yes, Viking. According to Wikipedia, this came from the name of a restaurant in Tokyo which first offered a buffet.
Meaning: condominium; mid-rise apartment building
English Cousin: mansion
Explanation: Apparently, real estate companies in the 1960s wanted to differentiate apartments with renters and more luxurious apartments for buyers. While there is overlap, マンション tends to be larger buildings with apartments owned by the residents instead of renting.
Meaning: You can do it! Do your best! Keep at it!
English Cousin: fight
Explanation: This is a substitute for がんばって！ because Japanese say がんばって too much. Well, at least, I think so. While this came from the English "fight," it is a term of encouragement.
Meaning: plastic bag
English Cousin: vinyl
Explanation: While in English "vinyl" brings old records to mind, in Japanese ビニール may bring a plastic shopping bag to a Japanese mind. It is used for any vinyl polymer plastics.
Meaning: air conditioner
English Cousin: cooler
Explanation: This one kind of makes sense. Just realize it doesn't mean a box to put your cold drinks in.
Meaning: wall socket; electrical outlet
English Cousin: concentric plug
Explanation: An old style of electrical plug which used round (concentric) plugs. This is one of those words that won't be helped by your English knowledge--unless you are an electrician and a historian.
Meaning: (Western) playing cards
English Cousin: trump
Explanation: Taken from the "trump card" in some card games.
English Cousin: Hotchkiss
Explanation: E. H. Hotchkiss Company: this company produced early staplers, and it became known by the company's name in Japan (and, according to Wikipedia, in Korea as well).
Meaning: survey; questionnaire
English Cousin: enquête
Explanation: Okay, this is a French word, but one that pops up often and sounds kind of like a mixture of "answer" and "question."
English Cousin: Roentgen
Explanation: From Wilhelm Conrad Röntgen who discovered and produced x-rays.
Meaning: microwave oven
English Cousin: range
Explanation: This may sound like an oven's range, but it is most often used for a microwave oven, also pronounced as 電子レンジ