It is all about the degree of certainty. "Maybe" and "perhaps" seem to be closer to each other in meaning and indicate a situation with lower degree of certainty then in the case of "possibly" which allows the listener to sense a slightly higher level of certainty. Using " probably" heightens the certitude and makes the thing prone to happen. The fact that something is happening in the near of far future makes the use of those words necessary, they reflect the limited capability of a human's mind to predict with 100% certainty the occurrence of future incidents.They are all acts of guessing , assuming , predicting or evaluating situations. "Mabye " and "perhaps" are rather guess works ,while "possibly" is an assumption and "probably" is nearer to prediction or evaluation.

Hello Eminov, The words "perhaps","maybe","probably" and "possibly" all indicate uncertainty and probability, not knowing exactly with certitude that something is taking place in the near or far future. However there are some slight differences,that determine preferring using the one over the other in a certain context, in other contexts they would fit as perfect "synonyms": - perhaps: means it is possible under certain circumstances. The condition and current situation will determine if that thing will happen or not. - possibly: It has the potential to happen , it is one option of many and likely to occur. -maybe: Yes and No ,being in a hesitant situation ,indecisive about something. - probably: It seems that it is prone to happen ,more likely to happen with high probability , there is a certainty degree when using probably. Examples: - Will you be able to come tomorrow? -" Perhaps , I can't tell you at this moment." *The person has to check his schedule, see if there are other things that might hinder him from going tomorrow. The situation will determine his decision. -"Possibly, I will try my best." * The person thinks it could happen and the situation allows it ,yet since there is still some uncertainty , he can't confirm it . - maybe: "Maybe , I didn't decide yet." * Both options and alternatives are likely to happen. Yes and No weigh the same. It is usually used when someone doesn't really know what is going to happen or didn't decide anything about the matter. -probably: "Probably , i will come , I have nothing special to do tomorrow." *Here the person is more likely to do the action. He has no hindrance, but can't confirm it 100%.

"Perhaps", "maybe" and "possibly" are synonyms. They can be used interchangeably. They indicate that something may happen but it's not for sure. "Probably" indicates that something is very likely to happen, but not for sure. "Surely" and "certainly" are synonyms. They can be used interchangeably. They indicate that something will happen, without question.

Eminov surely = конечно Friendship is fine , but love is surely better. certainly = непременно несомненно Certainly, the sun will shine again. probably = вероятно The boat didn't sink; it was probably captured by pirates. maybe = может быть maybe yes, maybe no perhaps = может быть Perhaps I will, perhaps I won't. possibly= вожможно St. Petersburg's "Zenith" is possibly the best football team in the world. What do you think?

This answer is a brief explanation. We need more time and examples for a full explanation. I hope the following helps (notice the word order): It is probably going to rain = you think rain will fall later - you see dark clouds in the sky. Perhaps is will rain = you think rain might fall later - there are some clouds far away. Maybe it will rain = you think rain might fall later - there are some clouds far away. There is a possibility of rain = you think rain might fall later - there are clouds far away. It is surely going to rain = you think rain is going to fall later - there are clouds overhead and you hear thunder. It is certainly going to rain = you know rain is going to fall later = there are clouds and you see rain falling in the distance. Please arrange a trial lesson for more details Anna www.englishharvest.blogspot.com