why some opponents time keep increasing at the end(2, 3sec)?

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healthtips123

Why does the time added continue after every move, at the end 2- 3 secs.

Fetoxo
If you are playing a time control with increment (for example, 3|2, 10|5, etc.), then an amount of time will be added every move.
bigD521

You have been playing increment. IE; 2/3. 2minute/3second. However long it takes to make a move the time is deducted and then the increment is added. Premoves only have a tiny bit of time deducted.