1 to demand

2 to request

3 to coerce

1 main

2 principal

3 major

4 primary

1 if only

2 so long as

1 necessary

2 essential

3 indispensable

4 required

1 to want to

2 to feel like

3 to fancy

4 to care for sb

5 desirous of

1 don't insist on only taking one road to Rome (idiom)

2 there's more than one way to skin a cat

1 a blade will get rusty if it is not sharpened; a man will fall behind if he doesn't study (idiom)

1 to hit the target and do real damage (idiom)

2 fig. to hit where it hurts

3 fig. to hit home

4 an argument that hits the nail on the head

1 lit. you can't expect the horse to run fast but not let it graze (idiom)

2 fig. you can't have your cake and eat it, too

1 If you work at it hard enough, you can grind an iron bar into a needle.

2 cf idiom 磨杵成針|磨杵成针, to grind an iron bar down to a fine needle (idiom); fig. to persevere in a difficult task

3 to study diligently