As most of you know, Japanese has a separate way of speaking to show politeness. This way of speaking is called 「敬語」 as a whole and is split into two levels: 1) Polite – 丁寧語, and 2) Honorific/Humble – 尊敬語／謙譲語. However, I’ve never really seen a neat term to describe the non-polite way of speaking in English or Japanese. Some might think that the opposite of polite is rude but the level I’m looking for is between the two. Slang is a little different too. What I’m referring to is a neutral way of speaking with equals. I’ve usually just called it “casual” or “dictionary form”. However, 「普通の話し方」 is rather unwieldy and 「辞書形」 is a term for conjugation, not a politeness level. I’m not aware of any formal term in Japanese which is a pain when making Japanese lessons so I looked up 「丁寧語の反対」 in Google and found my exact question on Yahoo!知恵袋. Say what you want about Yahoo and it’s past blunders with Microsoft but Yahoo Answers is really cool and turns up useful answers all the time.
I’ve decided to use the term 「タメ口」 based on this rather confident answer.
Any native speakers have any reservations with that term? Here’s a list of terms I tried to sort in order of politeness. Any additions, suggestions, or corrections appreciated.
By the way, I hope to use a screen sharing app during my lessons to show how to do this type of research using Japanese and the internet on your own.