Subject + haven't / hasn't + been + able to + infinitive Subject + have / has + been + able to + infinitive Was / Were + subject + able to + infinitive ? Subject + wasn't / weren't + able to + infinitive Subject + am not / isn't / aren't + able to + infinitiveĪm / is / are + subject + able to + infinitive ? Subject + am / is / are + able to + infinitive
