adv. 无疑;当然;确定;肯定;
💡 certain确实的+ly副词后缀,…地 → 确实地,一定地,当然地
"I shall certainly keep a beady eye on his behaviour."
我一定会时刻睁大眼睛提防他的行为。
近义:indeed, indubitably, inevitably, infallibly, assuredly, absolutely
反义:hesitatingly, hesitatively, indecisively, arguably, tentatively, wonderingly