Adverb
Without doubt or question; unquestionably.
Source: Webster's dictionaryWhen throwing dirt at a person, remember: dirt may not reach him, but on your hands it will certainly remain. Source: Internet
It is better to decide a difference between enemies than friends, for one of our friends will certainly become an enemy and one of our enemies a friend. Bias of Priene
You can't undo the past... but you can certainly not repeat it. Bruce Willis
If you don't understand it with a wink, you certainly will with a blow. Moroccan Proverb
A fruit tree that grows in a dung heap will certainly blossom. Zanzibar Proverb
If you are going to sit on it for three years, the seat will certainly get warm. Japanese Proverb