Put the verbs in brackets into Present Perfect or Present Perfect Continuous. Use only full forms

(meet)___ you__ Sally today?

Harry has been working for six hours but he (not, finish) ___ the painting yet.

Where do they live? — I know that they (move)__ to India.

I (practise) ___ playing the violin for 2 hours! I’m so tired!

They’re enjoying it! They (not be) ___ to a concert like this before.

Sure, here is a step-by-step solution to the exercise:

1. (meet) _Have you met_ Sally today?
To determine which tense to use, we consider if the action is completed or ongoing. In this case, meeting Sally is a completed action that happened at some point in the past. Therefore, we use the Present Perfect tense. We combine the auxiliary verb "have" with the past participle of the verb "meet" to form "have met."

2. Harry has been working for six hours, but he (not, finish) _hasn't finished_ the painting yet.
Here, we have an ongoing action that started in the past and continues up to now. To express this, we use the Present Perfect Continuous tense. We combine the auxiliary verb "have" with the present participle of the verb "finish" to form "hasn't finished."

3. Where do they live? - I know that they (move) _have moved_ to India.
Again, we are referring to a completed action. The fact that they moved to India happened at some point in the past. We use the Present Perfect tense by combining the auxiliary verb "have" with the past participle of the verb "move" to form "have moved."

4. I (practice) _have been practicing_ playing the violin for 2 hours! I'm so tired!
Here, the speaker expresses an ongoing action that started in the past and continues up to now. We use the Present Perfect Continuous tense by combining the auxiliary verb "have" with the present participle of the verb "practice" to form "have been practicing."

5. They're enjoying it! They (not be) _haven't been_ to a concert like this before.
This sentence is in the negative, stating that they have not had this experience before. Therefore, we use the Present Perfect Continuous tense. We combine the auxiliary verb "have" with the present participle of the verb "be" to form "haven't been."

I hope this explanation helps you understand the use of Present Perfect and Present Perfect Continuous tenses in the given sentences. Let me know if you have any further questions!