like in the title, verb & adj conjugations are todays brain buster.

I find it hard to work out the right question to ask, so i made a few simple ones (i think).

1: じゃ。why is is only used in the な adjective?

2: です。in adjectives and ます。for verbs. Why is that?

3: あるverb in ありません。why only in adjectives? (where verbs is only ます)

4: った。does it essentially indicate past tense for all adj?

5: ますーました。is it essentially ました = ます+した (from する). (same question for ません).

All and any thoughts appreciated. Thankyou for your time, Shaun.

https://www.japandict.com/ was where i looked through the conjugations

  • Please try to ask one question per question. – snailcar Mar 25 '18 at 10:20
  • ah, appologies and thank you for commenting. I found it really difficult in trying to segregate the questions and the context into individual questions without causing a deviation on the overall topic. – user26596 Mar 25 '18 at 11:00
  • @snail. I appologise if it's inconvenient, but i think it's relevant as a whole. – user26596 Mar 25 '18 at 11:16

I don't know if my answers are 100% grammatically accurate, but this is how I think about them:

1) The na-adjectives also behave as nouns. To use them as adjectives you add な.

This is a clean room.
This room is clean.

In the second example きれい acts as a noun, so to say this is not a clean room you'd have


in the same way that you'd happily write 犬じゃない. So, I don't see this じゃ as a conjugation, rather, it's just part of the negative copula (じゃない). You could equally well write きれいではありません etc.

2) ます is a polite conjugation of a verb. です only adds to i-adjectives. It is not a conjugation of the adjective, it is just added on to the end to make the sentence more polite. For example:


are both equally good, just with different levels of politeness.

3) You need to clarify this question. I don't understand what you're asking. If I had to guess, maybe you're thinking about things like きれいではありません, in which case, refer to 1).

Edit: Still not quite sure what you mean. You seem to be asking about negating adjectives. For i-adjectives you change the final い to a く and then add the negative form of the verb ある on to the end. That gives you a formal and an informal way to write it:

Formal: おいしくありません
Informal: おいしくない

Because ない itself behaves like an i-adjective the latter case can be made formal by adding です as discussed in 2):

Formal: おいしくないです

For the past tense conjugate ある just like you would if it was a stand-alone verb:


4) Not quite sure what you mean, but I'm going to say that the answer is yes. For an i-adjective you take of the final い and add かった:

おいしい -> おいしかった

For a na-adjective, as we discussed in 1), you conjugate the copula rather than the adjective:

きれいだ-> きれいだった
きれいです -> きれいでした

5) I doubt it, but I'm not even remotely qualified to answer that question. It's an interesting question, but probably not so helpful to your studies at this stage.

  • Thankyou for the great input. 1/ i can start to see what you mean with なadj and nouns. 2/ so ます is just a verb suffix for politelness, but is it a copula like です? 3/ Adj = く-ありませんでした, and で-はありませんでした. Verb = ませんでした . I hope that makes it clearer in the difference being the あるverb (i could be bloody wrong in my assumption though). 4/ i view it as the だ copula for な, か for い before the った. But i i see exactly what you mean. 5/ completely understand. Appologies, off to work so will be 12hrs behind. – user26596 Mar 25 '18 at 11:58
  • Still not sure I understand your problem, but see edit for 3/. As for 2/, the copula is just a fancy word for 'to be', so it doesn't apply to (other) verbs. It's either だ or です and you never use ます with these. There's another form of the copula which is である which can involve ます, but explaining that properly is getting out of my comfort zone, and probably not something you should worry about just yet. – user3856370 Mar 25 '18 at 12:42