I just cannot figure out if these answers are correct or not. Can you please help me?

78. If the sound system hadn’t failed, last night’s show would have been better.

This is a correct sentence using the 1st conditional form.

x This is a correct sentence using the 2nd conditional form.

This is a correct sentence using the 3rd conditional form.

This is an incorrect sentence.

79. They’ll work on new songs tomorrow if they would have time.

This is a correct sentence using the 1st conditional form.

x This is a correct sentence using the 2nd conditional form.

This is a correct sentence using the 3rd conditional form.

This is an incorrect sentence.

80. If the club’s manager agrees, they’ll play a few more original songs next time.

This is a correct sentence using the 1st conditional form.

This is a correct sentence using the 2nd conditional form.

x This is a correct sentence using the 3rd conditional form.

This is an incorrect sentence.

81. The duo could perform at weddings if Mike played the flute.

This is a correct sentence using the 1st conditional form.

x This is a correct sentence using the 2nd conditional form.

This is a correct sentence using the 3rd conditional form.

This is an incorrect sentence.

http://grammar.ccc.commnet.edu/grammar/conditional2.htm

Study this webpage, and then rethink your answers.

A person with brown hair may also exhibit the trait of brown eye color.

78. This is an incorrect sentence. The correct answer is "This is a correct sentence using the 3rd conditional form." The sentence is referring to a past event (the sound system failing) that affected the outcome of the show. In the 3rd conditional form, we use "if + past perfect" to talk about unreal past conditions and their hypothetical results.

79. This is an incorrect sentence. The correct answer is "This is a correct sentence using the 1st conditional form." The sentence is talking about a future possibility (working on new songs tomorrow) based on a possible condition (having time). In the 1st conditional form, we use "if + present simple" to talk about real possibilities in the future.

80. This is an incorrect sentence. The correct answer is "This is a correct sentence using the 1st conditional form." The sentence is discussing a future possibility (playing more original songs next time) based on an agreement from the club's manager. In the 1st conditional form, we use "if + present simple" to talk about real possibilities in the future.

81. This is an incorrect sentence. The correct answer is "This is a correct sentence using the 1st conditional form." The sentence is discussing a future possibility (performing at weddings) based on a condition (Mike playing the flute). In the 1st conditional form, we use "if + present simple" to talk about real possibilities in the future.

To determine if the answers are correct or not, let's review the different conditional forms:

1st conditional: Used to talk about possible future events or situations that are likely to happen.

2nd conditional: Used to talk about hypothetical or unreal situations in the present or future.

3rd conditional: Used to talk about hypothetical or unreal situations in the past.

Now let's analyze each sentence based on these forms:

78. "If the sound system hadn’t failed, last night’s show would have been better."
- This sentence is correctly using the 3rd conditional form because it talks about a hypothetical situation (the sound system failing in the past) and its potential outcome (the show being better).

79. "They’ll work on new songs tomorrow if they would have time."
- This sentence is incorrectly using the 2nd conditional form. It should be "They’ll work on new songs tomorrow if they have time" to correctly use the 1st conditional form, talking about a possible future event.

80. "If the club’s manager agrees, they’ll play a few more original songs next time."
- This sentence is correctly using the 1st conditional form as it talks about a possible future event (the club manager agreeing) and its potential outcome (playing more original songs).

81. "The duo could perform at weddings if Mike played the flute."
- This sentence is correctly using the 2nd conditional form because it talks about a hypothetical or unreal situation (Mike playing the flute) and its potential outcome (the duo performing at weddings).

Based on this analysis, the correct responses are:
78. This is an incorrect sentence.
79. This is a correct sentence using the 1st conditional form.
80. This is a correct sentence using the 1st conditional form.
81. This is a correct sentence using the 2nd conditional form.