What rule applies most closely to this word? deplor-

That is the root for the verb "deplore", which is used to express the dissaproval of something, or express condemnation or regret; thus one can use that root (in past tense) to state something was dissaproved with "deplored", we can use the gerund form "-ing" as "deploring", or we can even add the suffix -able to point out somethng as unworthy, deserving condemnation or regret with "deplorable".

Explanation:

with whom will you be coming to the party? this is written correctly.

answer: we need to see the ads : )