ADJ of n
The 'certain' and 'uncertain' group
These adjectives indicate that someone thinks something is true or will happen, or does not know what is true or will happen.
'We will improve, I'm certain of that,' he promised.
However, following talks with government officials, the union leader says he's hopeful of a settlement.
When there's a recession, you're bound to feel more out of control, anxious and uncertain of the future.
In the case of certain, confident, doubtful, hopeful, optimistic, and sure, the preposition of is sometimes followed by an '-ing' clause.
We are confident of forming the next government.
In the case of certain, sure, uncertain, and unsure, the preposition of is sometimes followed by a wh-clause.
certain confident convinced doubtful hopeful optimistic persuaded sure uncertain unconvinced unsure
I was unsure of what to do.