YOU SAID:

あれ は つくえ の せんせい です

INTO JAPANESE

あれ は つくえ の せんせい です

BACK INTO ENGLISH

That is the teacher at the desk.

INTO JAPANESE

机に座っているのは先生です。

BACK INTO ENGLISH

The teacher is sitting at the desk.

INTO JAPANESE

先生は机に座っています。

BACK INTO ENGLISH

The teacher is sitting at the desk.