Standing, sitting or crouching
1) Wherever we stand in the class, students will see us, therefore standing is important when we want the attention of the whole class, for clarifying language or giving instructions, for example.
2) Some experienced teachers know how to hold the attention of a large group while seated, but there is definitely a greater possibility of losing some learners’ attention if we are seated.
3) Another problem with sitting is the message it can give students. Whilst sitting down in front of students at the beginning of a class can create a welcoming, cosy atmosphere, if we are not careful, remaining seated throughout the class can give students the impression of a lack of interest and motivation on our part.
4) Our own body language plays a large part in the energy levels in our classroom, and it is difficult to create any energy if we remain seated the whole time.
5) There are times when sitting is a good idea, however. If standing can distract students and crouching for any length of time is physically uncomfortable, then sitting in a place which is easily accessible to all students while they are working, which may be in the middle of the class as opposed to at the front, has the advantage of not distracting them whilst leaving us available to answer any questions.
6) Crouching in, around or behind pairs and groups has several advantages. Firstly, we are giving the group the message that we are mobile, and not going to stay with one student, pair or group for longer than is necessary. Secondly, we are physically at the same height as the students, making interaction more personal and less threatening, which in turn leads to a more communicative atmosphere.
7) It should also be pointed out that, for obvious reasons, female students can feel uncomfortable with a male teacher standing over them. And finally, crouching allows us to position ourselves near pairs or groups without constantly moving furniture around with us, which can be very distracting.
https://www.teachingenglish.org.uk/article/teacher-positioning-classroom