There are 9 parts of speech or word classes in English language:
– nouns
– pronouns
– determiners
– verbs
– prepositions
– adjectives
– adverbs
– conjunctions
– interjections

We use adverbs to explain or describe:
– verbs,
– adjectives,
– other adverbs.

John speaks loudly.
– speak = verb
– loudly = adverb
– Adverb ‘loudly’ describes the verb ‘speaks.’

Mary lives there.
– lives = verb
– there = adverb
– Adverb ‘there’ describes the verb ‘lives.’

I saw John yesterday.
– saw = verb
– yesterday = adverb
– Adverb ‘yesterday’ describes the verb ‘saw.’

Jane is really beautiful.
– beautiful = adjective
– really = adverb
– Adverb ‘really’ describes the adjective ‘beautiful.’

She drives incredibly slowly.
– drives = verb
– slowly = adverb
– incredibly = adverb
– Adverb ‘slowly’ describes the verb ‘drives.’
– Adverb ‘incredibly’ describes the adverb ‘slowly.’

An adverb of probability tells us:
– the likelihood that something happens
– how certain we are of something

Adverbs of probability answer the questions of ‘how certain?‘

Maybe it won’t rain today.
– maybe = adverb of probability (explains how probable the rain happens today)

I will certainly talk to him tomorrow.
– certainly = adverb of probability (explains how certain the speaker of talking to him)

Obviously he will come tomorrow.
– obviously = adverb of probability (explains how certain the speaker of that person coming)

How to Use Adverbs of Probability

(1) ‘We usually use ‘perhaps’ and ‘maybe’ at the beginning of a sentence.

Perhaps the weather will be fine.
Maybe it won’t rain today.

(2) Adverb of Probability + Main Verb

Main verbs
– base form (walk, eat)
– past simple form (walked, ate)
– past participle form (walked, eaten)
– -s form (walks, eats)
– -ing form (walking, eating)

He is certainly coming to the party.
They will definitely finish the report on time.
We will possibly visit John this weekend.

(3) Verb be + Adverb of Probability

Verb be
– am/is/are
– was/were
– been
– being
– be

He was certainly there 15 minutes ago.
They are definitely tired.
She is possibly late.

Adverb of Probability List

These are some examples of adverbs or probability
– certainly
– definitely
– surely
– clearly
– obviously
– maybe
– possibly
– perhaps
– probably