Emphasis words are used to emphasize an adjective or adverb. They do not make use of comparatives or superlatives when making comparison of adjectives or adverbs. Often, grammatical mistakes are made when adjectives are used instead of adverbs, and vice versa.

Real is an adjective, really is an adverb.
EXAMPLE: The government is aware of the real problems that these people face. (CORRECT – real is an adjective used to describe the noun problems.)
EXAMPLE: The government is aware of the really problems that these people face. (INCORRECT – really is an adverb; an adverb does not modify a noun)

EXAMPLE: We don't know what real happened. (INCORRECT – adjective does not modify verb.)
EXAMPLE: We don't know what really happened. (CORRECT – adverb modifying verb.)

Certain is adjective; certainly is adverb.
EXAMPLE: Not smoking has certainly made a real difference. (CORRECT – certainly is an adverb and it modifies the verb made)
EXAMPLE: Not smoking has certain made a real difference. (INCORRECT – certain is an adjective and an adjective does not modify a verb.)

EXAMPLE: Are you quite certainly about what happened? (INCORRECT)
EXAMPLE: Are you quite certain about what happened? (CORRECT)