When it comes to ru-vebs there are a lot of weird things going on, but lets first look at irregular verbs since they are an easy exception. The irregular verb will have a る at the end of the word, but to determine if it is an irregular verb or not we need to look at the character before it. In the irregular verbs case you will either see a す or a く, so する or くる. Just remember the する or くる are irregular verbs.
Now that we have the main exception out of the way lets dig further into u-verbs or ru-verbs on verbs ending with る(ru). Unfortunately someone decided it was a good idea to confuse us all and make life a tad bit more difficult by making some ru-verbs u-verbs, but they did help us out a bit, only a bit. There is a way to determine if a verb ending in る is an u-verb or a ru-verb. Basically, it is decided by the sound before る.
If the sound before る is a, u, or o it is always an u-verb. So if you have a verb that the end sounds like aru, uru(minus exception above), or oru it is an u-verb. Lets take a look at a couple of examples.
のる
やる
かぶる
lets break these down to get the “sounds” to do this the easeist thing to do is just convert to romaji.
noru
yaru
kaburu
Now we have the romaji take a look before the ru. In red is the sound so. They are o, a, and u therefore they are u-verbs.
Next is verbs that are ru-verbs. To determine if they are actually ru-verbs we need to take a look again at the sound just before the る. In this case are are at iru and eru. If the sound is i or e most of the time it will be a ru-verb, we will talk about the exception after we look at some examples.
たべる
おりる
Now to break it down to romaji.
taberu
oriru
Again in red is the sound before ru. We have the sounds i and u so they are real ru-verbs.
So time for the exception to this rule, basically most of the time they are ru-verbs, but sometimes they are u-verbs. That is it, that is the explanation of the exception. I have talked to several people and the best explanation is “statistically speaking there are more ru verbs than uverbs”. And another person, my sensei, said “best way to know whether it is u or ru is to just memorize the exceptions because there isn’t a good way to tell.” Please if you know another way and are reading this let me know.
Hopefully, this is understandable for you I’ll leave you with some more examples for you to take a look at.
u-verbs
あそぶ (asobu)
いそぐ (isogu)
かえす (kaesu)
けす (kesu)
たつ (tatsu)
ru-verbs
あける (akeru)
おりる (oriru)
つける (tsukeru)
わすれる (wasureru)
しめる (shimeru)
irregular verbs
つれてくる (tsuretekuru)
もってくる (mottekuru)
けっこんする (kekkonsuru)
せんたくする (sentakusuru)
うんてんする (untensuru)
{ 1 comment… read it below or add one }
Thanks! My teacher hasn’t got round to explaining how to tell yet but I thought I should learn to make short forms easier ^^.
This is very useful.