Using 'desu'

Desu. is equivalent to English am/ are/ is, when expressing the identity of a noun; as in the examples below:

Weitaa desu. = (I/ You/ He/ She/ It) am/ are/ is a waiter.
Chikin desu. = (I/ You/ He/ She/ It) am/ are/ is chicken.

To make the statement a question, add -KA to the end of the sentence, as in the examples below:

Weitaa desu ka? = Am/ are/ is (I/ you/ he/ she) a waiter?
Chikin desu ka? = Am/ are/ is (I/ you/ he/ she) hot?

To make a statement negative one can use -janai desu as an equivalent to the English am not/ are not/ is not, as in the examples below:

*note: -i adjective do not follow this pattern.

Weitaa janai desu. (I/ You/ He/ She/ It) am not/ are not/ is not a waiter.
Chikin janai desu. (I/ You/ He/ She/ It) am not/ are not/ is not chicken.