Can I replace X with an adjective in 「ＸはＹです」?

Question

I have been learning Japanese for a month now, using various online sources and the Genki I textbook. In the textbook, lesson 1 introduces the 「ＸはＹです」sentence structure and although I'm way past this lesson, I always return to this concept because it's simple, yet confusing for me.

The grammatical explanation given to me was "X is Y. As for X, it is Y." Unlike the other sentence structures mentioned in the book, for example noun1のnoun2 (to express possession), there was no indication whether the X and Y variables in 「ＸはＹです」were supposed to be a specific part of speech.

I know I can replace the variables with nouns, for example 私はがくせいです to say "I am a student." And that they are interchangeable, for example がくせいは私です to say "The student is me.

If nouns are interchangeable, can a noun and an adjective be interchangeable as well? For example, 私はかわいいです (I am cute) to かわいいは私です(Cute I am). If not, is there a sentence structure where I can state the adjective first before mentioning the noun?

ありがとうございます！

Answer 1

X は Y です

• Noun, Noun Phrase ⇒ X
• Adjective, Noun, Noun Phrase ⇒ Y

かわいい by itself is an adjective, so it can't go into X

×「かわいいは私です」 - This is not OK

If you add の you can make a noun phrase and put that before the noun at Y

○「かわいいのは私です」 - This is OK

You can see more information about how の can be used to make noun phrases (nominalization) at the links below:

http://www.guidetojapanese.org/learn/grammar/nounparticles http://www.imabi.net/l112nominalization.htm