The prefix 'il' can be used. The complete word would be illogical.
illogical
The prefix In- can be added to numerable.
Speakable does not have a prefix as it is written. Speakable does have a suffix, -able. A prefix can be added to speakable - unspeakable.
The prefix 'im' can added to make the word impolite.
There is no prefix but there is a suffix -ly added to the word passive.Prefixes are added to the beginning of a word eg happy/unhappy prefix is un-
The prefix 'il' and or the suffix 'ly' may be used.
The root word of inconsequential is "sequential," which means following a logical order or sequence. The prefix "in-" added to "sequential" changes the meaning to "not following a logical order" or "not important."
The prefix that can be added to "please" is "dis-" to form "displease".
The prefix that can be added to the word "destructive" is "non-."
illogical
The prefix that can be added to appointment is "re-", forming the word "reappointment."
Impolite, unpolite
The prefix that can be added to "imperceptibly" is "un-".
The prefix added to "payment" to make it opposite is "non-."
Pre- is a prefix that can be added to the word monition.
The prefix In- can be added to numerable.
The prefix "non-" must be added to form the word "non-poisonous."