Learn English – ‘Would have + pp’ meaning

There are three kinds of if-clauses. In each kind of if-clause, the tense of the verb communicates two important ideas about the condition that affects the main clause of the sentence. The tense of the verb in the if-clause communicates:

1. The time perspective of the condition

AND

2. The nature of the condition

Let's consider the pair of Presidential conditions first:

If I became President, I'd be a good one. -- (said by schoolboy)

• Became is the past tense of become.
• The past tense creates a present time perspective, as in "If I knew, I would tell you," or, "If I had some money, I would buy that," (but the word became directs our attention to the future within that present time perspective).
• The past tense implies that the condition is improbable or impossible.
• The meaning of the sentence is:

"Probably, I am not becoming President, but I would be a good one, if I did."

It makes sense for a school boy's imagination to present that idea in a sentence. A school boy would not be in a position to say the second sentence about becoming President (of the United States) with any credibility:

If I had become President, I'd have been a good one.

• Had become is the past perfect tense of become.
• The past perfect tense creates a past time perspective.
• The past perfect tense implies that the condition is impossible.
• The meaning of the sentence is:

"I did not become President, but I would have been a good one, if I had."

Since a school boy is not old enough to run for President of the United Staes, it would have been nonsense, if he had said that. The sentence is something a loosing candidate might say.

The second pair of conditions communicates some impossible alternatives to a death condition:

If my mother were alive, she would be 80 next year.

• Were is the past tense of is.
• The past tense creates a present time perspective
• The past tense implies that the condition is improbable or impossible.
• The meaning of the sentence is:

"My mother is not alive, but she would be 80 next year, if she were."*

The words next year could create the same kind of time confusion as the word become did in the Presidential pair, but next year is in reference to the present time perspective. The other if clause communicates a similar meaning from a different perspective:

If my mother had been alive, she would have been 80 next year.

• Had had been is the past perfect tense of is.
• The past perfect tense creates a past time perspective.
• The past perfect tense implies that the condition is impossible.
• The meaning of the sentence is:

"My mother was not alive, but she would have been 80 next year, if she had been."

This construction is awkward, because the words next year seem to conflict with the past time perspective, but because death is a permanent condition, the meaning of the sentence survives well enough in the readers mind.

Conditional clauses can be confusing because:

1. The time perspective of if-clauses does not always match the tense of the verb.

AND

2. The verb also does the unique work of implying the nature of the condition.

This question only compared the second and third conditional clauses, but to put them in perspective.

First conditional:

• uses the present tense of the verb
• creates a present or future time perspective
• implies an open condition, that is something considered real or possible

Second conditional:

• uses the past tense of the verb
• creates a present time perspective
• implies an unreal, improbable or impossible condition

Third conditional:

• uses the past perfect tense of the verb
• creates a past time perspective
• implies an unreal impossible condition

Some instructors refer to a zero conditional as a special case of the first conditional.

1.If I needed more money in the future, I would have to do a better job.

Compare your sentence with: "I need more money, so I have to get a better job"

It is the same but yours is conditional, as you have said "only in the event A of would I have to do B".

2.Freddy sneezed on the cakes. He would have to go and do that.

This doesn't sounds right. Literally, your sentence means that Freddy was obliged to sneeze on the cakes. More normal would be:

"Freddy sneezed on the cakes. He would go and do that" - with emphasis on the would. The emphasised would here means that this is something typical of Freddy, because he is the kind of person who sneezes on cakes.

3.A: What did you do yesterday? B: I repaired the broken window. A: Ah yes, you would have to do that. Broken windows are dangerous.

Again in this example "would have" doesn't sound right. More logical here would be "should". Because repairing windows is something you should do, to prevent people injuring themselves. I tried to think of a logical way to write your sentence with "would have", and came up with:

"...Ah yes, you would have had to do that, because broken windows are dangerous". - That looks like quite a mouthful, but logically means "in the past, you were obliged to do that.