This is the 272nd most frequent Swedish word.
kunnat
"Kunnat" is the supine form of "kunna," meaning "been able to" in English.
Here, 'kunnat' is used in the pluperfect tense, along with 'hade' (had) as the auxiliary verb, to indicate a possibility that was not realized in the past.
Vi hade kunnat se filmen om vi inte hade varit för sena.
We could have watched the movie if we had not been too late.
Here, 'kunnat' is used as the past participle of the verb 'kunna' (to be able to), combined with the auxiliary verb 'har' (have) to form the present perfect tense.
Jag har inte kunnat besöka dig på länge.
I have not been able to visit you for a long time.
'Kunnat' is part of a conditional perfect construction, combining 'ha' as the auxiliary verb and 'kunnat' as the past participle of 'kunna' to express a hypothetical ability in the past.