“maybe” vs. “may be”
If "perhaps" can replace the word and the sentence still works, write the single word "maybe"; if the sentence needs "may" as a modal verb followed by "be" as the main verb, write the two separate words "may be."
maybe
"Maybe" is a single-word adverb meaning "perhaps" or "possibly" ("maybe we'll go tomorrow"). It formed in Middle English as a fusion of the phrase "it may be" (that), gradually contracting through frequent use into the single adverb we use today, the same pattern that produced other compressed adverbs like "perhaps" (from "per haps," by chance).
may be
"May be" is not a single word at all but the modal verb "may" followed by the base verb "be," used together to express a present possibility about a state or identity ("she may be the new manager"; "it may be true"). Each word keeps its own grammatical job: "may" signals possibility or permission, and "be" functions as the main verb of the sentence.
The real distinction
The test that resolves this pair almost every time is a simple substitution: try replacing the word or phrase with "perhaps." If "perhaps" fits smoothly at that spot in the sentence ("perhaps we'll go tomorrow"), you want the one-word adverb "maybe." If "perhaps" doesn't fit, and instead the sentence needs a modal verb followed by "be" acting as the main verb ("she perhaps the new manager" doesn't work, but "she may be the new manager" does), you want the two-word "may be." Another reliable check: "maybe" as an adverb typically sits at the start of a sentence or clause, modifying the whole idea that follows, while "may be" sits in the middle of a sentence functioning as the verb phrase itself, almost always followed by a noun, adjective, or another verb form describing a state ("may be right," "may be leaving," "may be the answer"). This is one of a small family of compound-versus-two-word confusions in English (alongside "everyday" versus "every day," and "awhile" versus "a while"), where a frequently used phrase eventually solidified into a single word while the original two-word phrase remained grammatically valid and distinct alongside it, leaving both forms correct but suited to different sentence structures. Style guides and grammar checkers increasingly flag this pair automatically, since it's one of the more mechanically testable confusions in English (the "perhaps" substitution works reliably almost every time), which makes it a comparatively easy one to fix once a writer learns the single test. It's also worth noting that 'maybe' as a sentence-opening adverb is sometimes flagged by formal style guides as slightly informal or hedging in tone, which is a stylistic consideration entirely separate from the spelling question but one that shows up in the same sentences often enough to mention alongside it.
Examples with “maybe”
- Maybe we should reschedule the meeting for Friday.
- I'll try the new restaurant, maybe this weekend.
- Maybe he just forgot to reply.
- She wondered if, maybe, the plan was too ambitious.
- Maybe it's time to consider a different approach.
- They'll join us later, maybe around eight.
- Maybe the weather will clear up by noon.
- He shrugged and said maybe he'd changed his mind.
Examples with “may be”
- She may be the best candidate for the role.
- This may be our last chance to fix it.
- The delay may be caused by a supply issue.
- He may be arriving earlier than we planned.
- That may be the strangest excuse I've ever heard.
- The results may be inconclusive until further testing.
- It may be worth asking for a second opinion.
- They may be waiting for us at the station.
Memory trick
Try the "perhaps" swap first, since it works almost every time: if "perhaps" fits, write one word, "maybe"; if it doesn't, write two words, "may be." As a backup check, notice that "may be" always has "be" acting like a regular verb right after it, describing a state or identity, the same job "is" or "was" would do elsewhere in the sentence.