How can we identify that if is of condition or of doubt?
To identify whether the conjunction, “if”, is used in case of doubt/uncertainty or condition, one has to understand the context of the sentence.
1. I have no idea if she is married.
2. I cannot say if it has stopped raining.
1. If you had come yesterday, you too would have received the gifts.
2. My mother would have cooked our favourite food if she had a holiday.