Command over the grammar is must. For a professional teacher, it is must to know what his students actually need to learn first.
What's the most challenging aspect of teaching English for you?
Being on time
I teach English covering speaking, writing, reading and listening to elementary and pre intermediate students. I am supposed to give the class exclusively in English to students whose L1 is Spanish. As I speak to them I can feel that they hardly understand. sometimes I am tempted to use Spanish but I refrain myself. This aspect of teaching English as a foreign language is the most challenging because they can write and read. They have a passive English. I have tried mimics and pictures.I teach grammar using examples of real life. This has been the most challenging Anyway I have been successfull
Here are a few sites to get pictures for ESL and foreign language teaching.
Clipart and Pictures for ESL and Foreign Language Teaching
What I found most challenging in training adult learners on communicative english is the challenge to reinforce something, make them aware of their mistakes and reduce the frequency of their errors. Most times, they are not receptive to feedback and improvement.
How to simplify a grammar topic, make it interesting and relevant by using scenarios instead of rules.
Is this more challenging in your current neck of the woods
What you meant by this expression and how can we use it in different contexts?
I guess some of them still think that is impossible.
I don't consider myself a good teacher (I don't have a vocation for that), neither of English nor anything else - I can only teach those ones who are willing to learn. And as Feynman once said, those ones do not really need a teacher.
Regarding learning English (or any other foreign language), the most challenging aspect I see is to prove the theoretical linguistics that their 'L1' theory is wrong.