Japanese Language - Na adjective

Now the fourth type of sentences is introduced.

Examples
1. Kono kaban wa joobu desu.
"This bag is strong."
2. Kono kaban wa joobu ja arimasen.
"This bag isn't strong."
3. Kono kaban wa joobu deshita.
"This bag was strong."
4. Kono kaban wa joobu ja arimasen deshita.
"This bag wasn't strong."
5. Kore wa joobu na kaban desu.
"This is a strong bag."
6. Kore wa joobu na kaban ja arimasen.
"This isn't a strong bag."
7. Kore wa joobu na kaban deshita.
"This was a strong bag."
8. Kore wa joobu na kaban ja arimasen deshita.
"This wasn't a strong bag."
As shown in the above examples, joobu desu has some functions that a noun has but also has some other functions just like an -i adjective. In other words, joobu desu comes at the end of a sentence. Also it modifies the noun it precedes. When -na adjectives modify a noun desu is changed to na.This kind of word will be called a -na adjective in this textbook.


Examples
1. Ruin san wa shizuka desu.
"Mr. Lwin is quiet."
2. Ruin san wa shizuka na gakusee desu.
"Mr. Lwin is a quiet student."
3. Kono shokudoo wa kiree ja arimasen.
"This cafeteria isn't clean."
4. Kore wa taihen na shukudai deshita.
"This was hard homework."