As can be supported or proven by sound logical deduction, evidence, and precedent.
Perhaps that is true (expressing no commitment to a decision or a neutral viewpoint to a statement).
Certainly.
Modifies a verb, indicating a lack of certainty: it may be (that)...
Possible; uncertain.
A future event that may or may not happen.
An answer that shows neither agreement nor disagreement.
Something that is possibly true.