Fill in the blanks using 'to be able to' according to the subject, respecting the verb tense and type of sentence indicated in parentheses. In case...

Fill in the blanks using 'to be able to' according to the subject, respecting the verb tense and type of sentence indicated in parentheses. In case there is a frequency adverb, pay attention to its position in the sentence. If the sentence is negative, use the contracted form.
She is able to  serve tables and prepare drinks. (be able to – present simple – affirmative)
They have always been able to  achieve their goals. (be able to – present perfect – always – affirmative)
I wasn't able to  study for the test, so I doubt I did well. (be able to – simple past – negative)
Steve and Oxley aren't able to  get along well. (be able to – present simple – negative)
Bruno has never been able to  understand Physics. (be able to - present perfect - never - affirmative)
Sarah and Amélie were able to  cover their friend's shift. (be able to – past simple – affirmative)