Working on this subject
Concepts, then drills, then the clock
Read the explanations
Including on the questions you got right. The working transfers; the answer key does not.
Practise in your medium
English and हिन्दी are the same question behind a toggle, so progress carries across.
Then take it timed
Once the subject stops surprising you, mix it into a timed paper and see whether it still holds under a clock.