Can we say probable where we have to say possible?
What is the exact meaning of that? I have searched this, but I didn't get the perfect example of that.
The answer to your question is not quite as easy as it should be.
The reason for this is that both "possible" and "probable" are also technical terms. So while some may use the words ordinarily, others may use them technically.
The ordinary meaning of the word "possible" is that which is able to occur.
The ordinary meaning of the word "probable" is that which is likely to occur.
The technical meaning of the word "possible" is something like: it is not necessary for it not to occur.
The technical meaning of the word "probable" is the description of the statistical outcome of an event or a series of events.
In ordinary English we can (and often do) interchange the terms possible and probably. E.g. "I can probably to go the party tonight. Is it possible you are going too?" However, the connotation of each is still likely to occur and able to occur respectively.
To further illustrate the technical use, I'll end with a joke:
Three logicians walk into a bar. The bartender asks if they would all like a drink. The first logician says "I'm not sure." The second logician says "I'm not sure." The third logician says "Yes."
Two major groups of modals are the Necessary (⃞ 'Square') and Possible (⃟ 'Diamond') modals. Necessary and Possible are defined logically this way (where p is any proposition):
And they're laid out on a line from ¬ ⃟ (Impossible) at one end, with ⃞ (Certain) at the other, with Possible at the zero point, and varying degrees of (im)probability spread out among them.
These are all judgements, predictions of events. As such, they're not easily verifiable, especially in cases of unique events. But they are ways of expressing those judgements.