kun je ook gebruiken in plaats van can, maar
to be able to is veel
formeler.
To be able to kun je in alle tijden gebruiken:
1. I am able to ( can) to go to the party with you. ( t.t)
2. It was hard work and we were able to finish it in time( v.t + specifieke gebeurtenis dus could is niet mogelijk)
3. It was hard work,and we couldn't/ weren't able to finish in time. ( v.t+ specifike gebeurtenis MAAR het is ONTKENNEND)