What is the difference between "maybe" and "may be"?

What is the difference in meaning and usage between maybe and may be? Are they synonymous?

Solution 1:

maybe is an adverb, meaning perhaps or possibly.

may be is a verbal construction, formed of the modal verb may and the verb be, which can be used in sentences like “he may be in the office today”. Note that, if you were to rewrite this sentence with maybe, you would say “maybe he is in the office today”. Because maybe is an adverb, you need to add a verb to the sentence (is, a form of be, in that case).

Solution 2:

Maybe is an adverb, with means possibly or perhaps; may be is a verbal phrase.

Maybe you are wrong.
It may be true.

As per the origin, the NOAD reports that the origin of maybe is late Middle English, from the phrase it may be (that).