It depends on what you are communicating. You could add -ed, -ing, -er, for example.
after
The prefix of the word "postdoctorate" is "post-" and the suffix is "-ate."
Postdoctorate has a prefix of 'post' meaning after, and a suffix of 'ate' making it an adjective/descriptive word.
Paid is the root word. Post- is the suffix.
after birth. Post means after. Natal means birth.
What do you mean? Do you know what a "sufix" (it's actually spelled "suffix") is? The word makes no sense in this context. Perhaps you mean "acronym", in which case the answer is "PTSD".
Ah, let's take a moment to appreciate the word "posture." The prefix is "post-" which means after or behind, the root is "post" which refers to position or place, and the suffix is "-ure" which is used to form nouns. Just like painting a happy little tree, breaking down words can be a peaceful and enlightening experience.
"Mission" is a root word. It has neither a suffix nor a prefix. Transmission and missionary are words with a prefix or suffix attached to the root word "mission."
The suffix for undo is to not do.
the suffix is on
There is no suffix in misjudge.
The suffix of inundate is -ate. This suffix means in condition of.