また、今日、

The indicator of tense in any sentence ALWAYS comes at the end, be it a clause or the entire sentence. The complications with the adjectives in this lesson actually hint at one of the nuances a lot of students miss: that the meaning of “to be” automatically exists in all ~い (i) adjectives. です (desu), though it does mean “to be,” is only used here to add politeness, not the meaning of “is.” For example:

今日は暑いです。kyou wa atsui desu (it is hot today)
今日は暑い。kyou wa atsui (it is hot today)

Both sentences contain the meaning of “is,” yet only one of them contains です (desu). です, again, ONLY adds politeness. The meaning of “to be” is already there in the い (i) adjective. The mistake a lot of people make is trying to add だ (da) onto an い-adjective in informal speech, but this is WRONG:

今日は暑いだよ。kyou wa atsui da yo (wrong!)
今日は暑いよ。kyou wa atsui yo (the proper informal!)

Just as you cannot say

難しかっただ muzukashikatta da (wrong!)
難しかった muzukashikatta (correct)

Note that this is only the case with い adjectives, for な(na) adjectives, you still need だ or です. It’s a useful point, because I have heard even intermediate level speakers make this mistake.

Jean-Michel

えいがはおもしろいです。 present
えいがはおもしろくないです。 present negative
えいがはおもしろかったです。 past
えいがはおもしろくなかったです。 past negative

えいがはゆうめいです。 present
えいがはゆうめいでわありません。 present negative
えいがはゆうめいでした。 past
えいがはゆうめいでわありませんでした。 past negative

For me, the tricky thing is that sometimes the verb (です） is conjugated and sometimes the adjective is conjugated. In the case of the い-adjective, it is the adjective that is conjugated. In the case of the な-adjective, it is the verb that is conjugated. We just need to remember that な-adjectives are like a noun and nouns don’t get conjugated.

The next thing here is that when い-adjectives are used in front of a noun there is NO CONJUGATION. From Page 65.

らしょうもん（羅生門）は　おもしろい　えいが　でした。

So the verb conjugates the tense here. Compare with

らしょうもん（羅生門）は　おもしろかった　です。

So this seems a little confusing. In one case we have でした　and the other we have です。 But they are both in the past tense. We don’t conjugate adjectives when they are in front of nouns.

As for the stringing of adjectives together, we use the くて　or で　for the い　and な　adjectives, respectively. But the last adjective is treated as normal.

I think all your examples here are right.
おもしろくてたのしかった(です)
ゆうめいでおもしろかった(です)
おもしろくてゆうめいでした
おもしろくてゆうめいだった
きれいなドレスを買いました。
おもしろい本 を買います

For the last one, in the past tense we leave the adjective alone because it is in front of a noun.
おもしろい本 を買いました。
I think this is correct and hope this is helpful. In any case, it was helpful to me to review this things. You asked some great questions.
じゃ　また
ジョン

And how about the informal phrase:
おもしろくてゆうめいだった ?

Is it correct?

Finally, I can write:
きれいなドレスを買いました。
for “I bought a nice dress”, since きれい is a な adjective;
but how would I put : おもしろい本 を買います　(”I buy an interesting book”) in the past tense? Am I supposed to put BOTH the (い) adjective おもしろい and the verb 買う in the past tense?
Here, it seems I’m getting confused…

Has anybody got an idea?

Jean-Michel

For i-adjectives that you are connecting, drop the い and add くて. For な-adjectives, you connect using で and don’t use the な。 But I think you know this already.

Your question is about the present versus past form. The answer is that the last adjective controls the tense. Here is the example from the book.
　りょこう、ど　だった？
　　　たのしけて、すばらしかったわ。
This is obviously informal, but it shows the idea. The last adjective controls the tense.
じゃ　また
ジョン

So, let’s see if someone is listening to those RSS feeds !…
I had this question in the back of my mind for some time, as it seems that textbooks typically introduce the conjunction of two adjectives in the present tense, then forget to mention what happens when going the past tense.
Since tha past tense of adjectives has just been introduces in Lesson 68, I thought it may be time to ask

Say, if I have, in the present :　おもしろくてゆうめいです。
The past tense should be, if I take each adjective separately:
おもしろかったですand ゆうめいでした。(hope this is right )
How do I make the connection now?

And how about the reversed case : ゆうめいでおもしろいです ?

and the connection of ゆめいなひと + おもしろいひと (or vice versa), in the present and past tenses ?

So many cases I cannot find in my grammar books !… (even restricting myself to the informal case)

Can anybody help ?

Jean-Michel