The visa officer is not testing your English. They are testing if they can trust it.
Most people fail visa interviews in the first 20 seconds, and it is not because their English is “bad.”
It is because they talk too much.
The officer asks: “How long will you stay?”
They answer with a story about their uncle, shopping, maybe New York, maybe a wedding, maybe leave from office.
The officer only needed a number.
If you are Indian and you have a US, Canada, or UK interview coming, practice this structure until you can say it without looking down:
“I work as a [job] at [company] in [city]. I earn [amount] per month. I am going for [X] days to [place] for [reason]. I return on [date] because I have [job / family] in India.”
That is the whole interview for a lot of people. Everything else is a follow-up.
Three rules I make every student follow:
Tell the truth. Your form and your mouth must say the same thing.
One idea per sentence. No “actually”, no “basically”, no extra relatives.
If you do not know, say “I do not know. I can check my documents.” Guessing a date is worse than silence.
Record yourself on your phone. If the answer is longer than 15 seconds, cut it.
English practice only. Not legal advice. If your interview is in the next 30 days, start with those 8 facts on one page. Then speak.