Solution:
- 1. If I had more money, I'd buy a faster car. (Second conditional uses 'had' for the past tense of 'have' in the 'if' clause.)
- 2. If Paul practised more, he'd join the team. (Second conditional uses the past tense 'practised' for the 'if' clause.)
- 3. If I were you, I would practise more. (Second conditional uses 'were' for 'be' in the 'if' clause, even with 'I'.)
- 4. If they went to the party, they would have fun. (Second conditional uses the past tense 'went' for 'go' in the 'if' clause.)
- 5. If we had enough time, we would play a game. (Second conditional uses 'had' for the past tense of 'have' in the 'if' clause.)
- 6. If she played the piano, she would be in the band. (Second conditional uses the past tense 'played' for 'play' in the 'if' clause.)
Note: The verbs 'be', 'have' were used twice as indicated in the question.