1.不用变也可以，详细如下：
‘May’ or ‘might’?
May and might are both ways of expressing possibility. Is there a difference between the way in which they should be used?
Some people insist that you should use may (present tense) when talking about a current situation and might (past tense) when talking about an event that happened in the past. For example:
I may go home early if I’m tired. (present tense)
He might have visited Italy before settling in Nuremberg. (past tense)
In practice, this distinction is rarely made today and the two words are generally interchangeable:
I might go home early if I’m tired.
He may have visited Italy before settling in Nuremberg.
But there is a distinction between may have and might have in certain contexts. If the truth of a situation is still not known at the time of speaking or writing, either of the two is acceptable:
By the time you read this, he may have made his decision.
I think that comment might have offended some people.
If the event or situation referred to did not in fact occur, it's better to use might have:
The draw against Italy might have been a turning point, but it didn't turn out like that.
May and might are both ways of expressing possibility. Is there a difference between the way in which they should be used?
Some people insist that you should use may (present tense) when talking about a current situation and might (past tense) when talking about an event that happened in the past. For example:
I may go home early if I’m tired. (present tense)
He might have visited Italy before settling in Nuremberg. (past tense)
In practice, this distinction is rarely made today and the two words are generally interchangeable:
I might go home early if I’m tired.
He may have visited Italy before settling in Nuremberg.
But there is a distinction between may have and might have in certain contexts. If the truth of a situation is still not known at the time of speaking or writing, either of the two is acceptable:
By the time you read this, he may have made his decision.
I think that comment might have offended some people.
If the event or situation referred to did not in fact occur, it's better to use might have:
The draw against Italy might have been a turning point, but it didn't turn out like that.
2.may/might区别
if you say that something may or might be true or that it may or might happen, you have some reason to believe that it will happen or that it is true, but you are not certain; may is more common than might in written English, might is more common than may in spoken English [modal verb]
比如
Take your umbrella -you might need it. | The report states that the man may have been murdered. | I've got a meeting this evening, so I might be a little late home tonight. | Employees are expected to deal pleasantly and efficiently with any problems that may arise.
3.may：might 区别
1a．这两个情态助动词所含的意境色彩不全一样：前者含有“可能”的义蕴（参见词目563），而后者则多少含有“推测”或“假定”的义蕴（注：无怪有的语法学家认为，这两者是两个截然不同的情态助动词）。
例如：The
cold weather may remain for a month．这样寒冷的天气可能会维持一个月。（表示可能）
You may come any
day you like．你随便哪一天来好了。（表示许可）
This wire might hold．这根铁丝可以摸得。（＝…if youwould
try）
Phil might do this job well．菲尔干得了这种活。（=…ifwe were to give him the
opportunity）
比较：Eddie may have warmed up，I
suppose．我看，埃迪可能已在劲头上了。（可能性较大）
Eddie might have warmed up，I
suppose．我看，埃迪也许已在劲头上了。（可能性较小）
1b．因此，过去时间要用may have been来表达，不用might
be来表达。
比较：His failure to come back may be due to his
illness．他没有能够回来，可能是因病。（表达现在时间）
His failure to come back may have been due to
his
illness．他没有能够回来，可能是因病。（表达过去时间）
1c．同前者又不一样，后者用于
现在完成时态，往往表示可能发生而未成为事实的可能性——甚至含有否定的意味。
比较：Polly's
very late．—She may have missed her
train．波莉这样晚还不见来。——可能她没有赶上火车。（指的是过去的时间，所以可能是事实）
You were stupid to try
climbing up there．You might havekilled
yourself．你想到那里去攀登，真是傻。你可能会摔死的。（并未成为事实）
2a．表达许可，两者都可使用，只是后者含有“试探”和“犹豫”的义蕴，而前者则没有这样的含义。
例如：May
I turn the TV on？我可以把电视机拧开吗？
I wonder if I might have a little more
cheese．我想再要点奶酪，不知行不行。
2b．因此，用于疑问结构，使用前者比较客气；使用后者则在口气上多少带有“不好意思”的神态。
比较：May
I borrow your bicycle fof a while？我可不可以借你的自行车用一下？
Might I borrow your bicycle
for a while？向你借用一下自行车，你看怎么样？