maybe,possibly,perhaps,probably
这四个词都可表示“可能性”.
maybe：“可能,也许”,比其余的几个词更为随便和不正式,可能性不大,也可以表示一种非常委婉,礼貌的建议或要求.如：You could put it over there,maybe.也许你可以把它搁在那边.
He didn't feel quite right; maybe he got sunstroke.他觉得不太好；也许是有点中暑.
The doctor thinks maybe we'd better have a minor operation.医生认为也许我们最好做个小手术.
possibly：“可能地,或者,也许",可能性较大.用于否定句和疑问句时表示 "无论如何"之意.
She expressed regret for any inconvenience which might possibly be caused.
她为任何可能造成的不便而深表歉意.
I couldn't possibly have finished typing such a long document in such a limited period of time.无论如何,我也不可能在如此有限的时间内打完这么长的文件.
perhaps：“可能”,较为常用也较为正式的词,可能性也不十分大.它可以表示建议或要求,也可以表示以礼貌的方式下命令.
I thought perhaps it was the letter you had been expecting.我想这大概是你一直盼望的那封信.
Perhaps you will kindly give us a hand when we are in trouble.当我们陷入困境时,也许你会善意地帮我们一把.
probably：“很可能,大概”,可能性在这一组词中最大,表示一种几乎完全肯定的意思.
He is the only witness of the accident; he can probably give us some detailed information about it.他是这次事故唯一的目击者,他大概可以告诉我们一些详细情况.
There is probably some kind of living matter on some other worlds,but we do not know yet.很可能在其他的世界存在着另类的生物,只是我们尚不知道.
probably,possibly,maybe,perhaps
副词 probably,possibly,maybe,perhaps 都表示可能性,但在程度和用法上稍有不同.
perhaps 作“或许”解,有“也许如此,也许不如此”的意味.它和 possibly的意味相似,但 possibly 通常与 can,may,must 等词连用.例如：
这也许是真的.
maybe 也作“或许”解,同 perhaps 意思接近,但比 perhaps 更为普通而又不那么庄重.perhaps 是英国英语,maybe 是美国英语.例如：
Perhaps/Maybe it is true．
probably 也作“或许”、“可能”解,是 most likely (很可能)的意思.它比perhaps 和 possibly 所表示的可能性大.例如：
是“他或许会成功”的意思,含有“不会成功”的意思较多.likely 是形容词,也有“很可能”的意思,大体上和 probable 同义,但比 probable 更为多用.在用法上也有些不同.likely 之后常跟不定式(be likely to do sth),而 probable 之后通常不跟不定式.例如：He is likely to come．(他很可能会来),其中的 likely 不可用 probable 代替.但是在 It is likely that he will come．中的 likely 都可以用 probable 代替.