# Conditionals , What are the differences?

What is the difference between the two sentences:

1. If I won the lottery, I'd buy a big house.

2. If I had won the lottery, I'd have bought a big house.

My guess is that the first sentence is mere imagination from the speaker. The second sentence is that he actually betted on a lottery and failed.

Another point is that if the second conditional sentence denotes "present tense," then what is the difference between it and the first conditional?

Am I right on that ?

Conditional I

If it is possible but very unlikely that the condition will be fulfilled, use `if + Simple Past, Conditional (Would + Infinitive)`

If I won the lottery(if + simple Past), I'd buy a big house (conditional).

You can win the lottery, it is possible, but the chance of winning the lottery is very unlikely.

Example 2:

If I found her address, I would send her an invitation.

I would like to send an invitation to a friend. I have looked everywhere for her address, but I cannot find it. So now I think it is rather unlikely that I will eventually find her address.

Conditional II

If it is impossible that the condition will be fulfilled because it refers to the past, use `if + Past Perfect, conditional (would + have + Past Participle)`

If I had won the lottery (if + past perfect), I'd have bought a big house (conditional).

This means that some event/action happened in the past and, thus, you can not change it or the outcome of it. There is no chance of winning that lottery.

Example 2:

If I had found her address, I would have sent her an invitation.

Sometime in the past, I wanted to send an invitation to a friend. I didn't find her address, however. So in the end I didn't send her an invitation.

So, yes, you are right.

Now, coming to your second query. If you use simple present, it becomes:

If I win the lottery, I will buy a big house.

we use this conditional sentence when it is possible and also very likely that the condition will be fulfilled.

Example 2:

If I find her address, I’ll send her an invitation.

I want to send an invitation to a friend. I just have to find her address. I am quite sure, however, that I will find it.

More on Conditional sentences here

• Thanks for your reply but I understood from it that there are 2 impossibles .... 1) Impossible because something is very unlikely to happen (like imagination), so we use the Second Conditional. 2) Impossible because we cannot change the past .. (it is likely to be an event) ... then we use the Third Conditional. Is that true ? Oct 17 '15 at 14:25
• @GamalThomas in the first conditional (If I won the lottery, I'd buy a big house), It is not Impossible, but very unlikely(yes, like imagining). Very unlikely means that it has a chance of being right/true, it does not mean it is impossible. In the second Conditional, It is impossible because we can not change the past. Oct 17 '15 at 14:31

The difference is tense.

Second conditional is used for events that are unlikely to happen in the present or future.

If I won the lottery, I'd buy a big house. (I don't earn it, so I don't buy the house.)

The third conditional is used to speculate about an imaginary result of things that didn't happen.

If I had won the lottery, I would have bought a big house. (I didn't win the lottery, so I didn't buy the house.)