Maybe... / Perhaps...
Can take indicative (more certain) or subjunctive (more doubtful). Quizás venga = maybe she'll come (doubtful). Quizás viene = maybe she's coming (more likely).
Maybe it's better to wait until tomorrow.
Perhaps he's right and we're the ones who are wrong.
—Are you up for it? —Maybe, let me think about it.
Perhaps he's right.
Maybe we'll go to the movies.