Adverbials of probability
We use adverbials of probability to show how certain we are about something. The most frequent adverbials of probability are:
certainly - definitely - maybe - possibly
clearly - obviously - perhaps - probably
maybe and perhaps usually come at the beginning of the clause:
Perhaps the weather will be fine.
Maybe it won’t rain.
Other adverbs of possibility usually come in front of the main verb:
He is certainly coming to the party.
Will they definitely be there?
We will possibly come to England next year.
but in after am, is, are, was, were:
They are definitely at home.
She was obviously very surprised.