I would probably have said something like this.

I find the sentence somewhat unnatural. Personally, I would probably have said something like this.

I know that the structure “would have + past participle” is past unreal conditional but I wonder what is the full form of it.

If I had been in that situation(or something similar), I would probably have said something like this.

Hi Screen,

Are you questioning the use of ‘I would probably have said something like this.’ alone? In other words, are you saying that you find that sentence unnatural without an IF clause?

If so, there is no need to worry about that. There are frequently situations in which the IF-clause (i.e. the condition) is clearly implied and does not need to be stated. In fact, forcing the addition of an already understood IF-clause would tend to make the sentence less natural in the context – because it would be unnecessarily wordy.

So, yes, the implied IF clause would be something similar to what you suggested, and the verb form you suggested (past perfect form: ‘had been’) is appropriate.

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Thanks Esl_Expert!
It is part of my intended question. I am happy to know it too. Sorry for not being clear.
The context is something like this:
Someone asked a question about English and a teacher answered it as follows.

“I find the sentence somewhat unnatural. Personally, I would probably have said something like this.”
I would like to know if the sentence bellow is the full form of it or not.

If I had been in that situation(or something similar), I would probably have said something like this.