Certainly
Assuredly
Synonyms: Unquestionably, assuredly, beyond question, beyond doubt, indubitably, irrefutably, incontrovertibly, obviously, manifestly, plainly, transparently, unmistakably, undisputedly, there are no two ways about it, surely, definitely, without question, unequivocally, undeniably, indisputably, incontestably, patently, evidently, clearly, palpably, conclusively, undoubtedly, and as sure as eggs is eggs.
Admittedly
Synonyms: Admittedly, without question, undoubtedly, beyond question, definitely, and without a doubt.
Absolutely
Synonyms: Yes, absolutely, by all means, indeed, positively, without doubt, unquestionably, rather, definitely, sure, quite, of course, naturally, without question, and affirmative.
Example Sentences
I will certainly help you tomorrow.
She will certainly attend the meeting.
He certainly understands the situation now.
They certainly enjoyed their vacation immensely.
You can certainly count on me.