Present Perfect Continuous Tense

The present perfect continuous tense requires the auxiliary verb 'has' for a third-person singular subject ('your dad').

The present perfect negative form for a third-person singular subject is 'has not' (hasn't) plus the past participle 'seen'.

The present perfect continuous structure is 'have/has' + 'been' + verb-ing. 'Been seeing' fits this pattern.

'For' is used to indicate a duration of time (2 hours), whereas 'since' is used for a specific starting point in time.

'Still' is used to indicate that a situation continues to be the case, often used in negative sentences to show something hasn't happened yet.

'Yet' is the standard adverb used in negative present perfect sentences to indicate something expected has not occurred up to the present.

'Since' is used to denote a specific starting point in time (high school).

The present perfect structure 'Have you ever' requires the past participle of the verb, which is 'visited'.

The present perfect continuous tense requires the '-ing' form of the main verb ('studying').

When referring to a duration of time (years), 'for' is typically used, but 'in' is also common in negative sentences to indicate the duration since the last occurrence.

The present perfect continuous structure requires 'been' + verb-ing. 'Doing' is the correct participle form.

The question asks about recent activities, and 'recently' is the appropriate adverb to complete the present perfect continuous construction. Other options like 'usually' or 'last week' do not fit the grammatical structure of the sentence.

The preposition 'since' is used to indicate a specific point in time when an action began. 'For' would require a duration of time, and 'in' or 'already' do not fit the context of a starting point.

The sentence uses the present perfect continuous tense, which requires 'been doing' to describe an ongoing action that started in the past. Other options do not fit the auxiliary verb 'have'.

The present perfect tense requires the past participle 'done' after the auxiliary verb 'have'. 'Been done' is passive and incorrect in this active context.