Spoken English?

Liton Das

Interviewer - Can you speak in English fluently with the students? As it is the very first requirement to be selected as a teacher in an English medium school.

Why would the interviewer ask such idiotic question? He should assume that he can communicate in English fluently.

Candidate - I can speak in English but not that much great as it is not my mother tongue, but I can assure you that once I get selected here as a teacher and start giving lessons and classes in English it will improve and have a great positive impact on my spoken English also once I start practicing English it will improve the English speaking skills over the period of time.

This is a strange interview. The person being interviewed is supposed to be an applicant for a teaching position in a high school. But if he admits himself that his English is not that fluent because it is not his mother lounge, how can he be qualified for the job and assure the interviewer that he will improve after he gets the job? I am not sure what you want from the us as helpers? The dialogue is not making sense.

Liton DasInterviewer - Can you speak in English fluently with the students? As it is the very first requirement to be selected as a teacher in an English medium school.

The second sentence is not grammatically complete. Sometimes that's OK, but not this time."Requirement to be selected" is unidiomatic.

Maybe "This is the very first requirement for selection as a teacher in an English medium school."

Liton DasCandidate - I can speak in English but not that much great as it is not my mother tongue, but I can assure you that once I get selected here as a teacher and start giving lessons and classes in English it will improve and have a great positive impact on my spoken English also once I start practicing English it will improve the English speaking skills over the period of time.

That is one long breathless sentence. It is so long it goes beyond style error to plain old error. Taking a piece at a time:

Liton DasI can speak in English but not that much great as it is not my mother tongue,

We say "speak English", not "speak in English" in this context. "Not that much great" is unidiomatic. Try "not as well as I want". That English is not your mother tongue is no excuse, and you only reveal that you don't realize that by saying that here.

Liton Dasbut I can assure you that once I get selected here as a teacher and start giving lessons and classes in English it will improve

"Get selected" is informal. "Lessons and classes" sounds redundant, whether it is or not. "It" has no antecedent. End the sentence here.

Maybe: "but I can assure you that once I am selected here as a teacher and start teaching in English, my fluency will improve."

Liton Dasand have a great positive impact on my spoken English also once I start practicing English it will improve the English speaking skills over the period of time.

"Great positive impact on" is empty cliche. You pretty much say the same thing three times. The two definite articles are unidiomatic. I would delete this whole part.

It's just a imaginary talk between an applicant and the interviewers just to learn something how to form correct paragraph.

Actually, here in India there are some private undertaking schools in rural areas, which offer very less salary to work in their school, and the interviewers know very well that no one would come here to work for such a penny amount, because if they were fluent in English then they would have been recruited in big schools offering them a good amount as a salary which makes no point for them to come to these schools for an interview.

Here in private schools the salary is like 96 dollars only which converts to almost 6800 Indian rupees.

Although, the point of creating this thread is to get the paragraph corrected so that I could learn something and take some notes pf it.