Being able and having to (potrafić, być w stanie, dać radę, należy)

Three ways to say "can"

You know móc (to be allowed / to be able in the circumstances) and umieć (to know how). to be able to, to know how to

potrafić — to be able to, to know how to — overlaps with umieć but stresses the capability, including one-off achievements: on potrafi naprawić wszystko. It conjugates like robić: potrafię, potrafisz, potrafi.

to be able to, to be in a position to (+ infinitive)

być w stanie + infinitive — to be able to, to be in a position to — about having the strength, time or means: nie jestem w stanie tego zrobić sam.

to manage, to cope (dam radę!)

dać radę — to manage, to cope — perfective; the reassuring dam radę! (I'll manage). Negated it takes the Genitive: nie dałem rady.

It can(not) be done

it can't be done, it's impossible (da się: it can be done)

nie da się + infinitive — it can't be done, it's impossible — an impersonal predicate with no subject; positive da się — it can be done. The object goes into the Genitive under negation: tego nie da się naprawić.

One should

one should, it is necessary to (impersonal, + infinitive)

należy + infinitive — one should, it is necessary to — the impersonal predicate of rules and instructions, more formal than trzeba. Past należało, future będzie należało.