the word post has several meanings. the following sentences illustrate them:
please post the letter.
post the item to the inventory list
tie the rope to the post.
You can post a question to the internet about how to use it in a sentence.
Yesterday I went to the post office to get some stamps.
There was a time when Mesopotamia was a trading post.
Aquiring the command post was of upmost imperativeness.
the post-industrial age of America was vast.
*postmortem*"the postmortem of the man was unbearable."
There are many post doctoral fellows in our school.
It would dissatisfy me greatly if you were not to use this post.
As a noun: Once you sink the post, I'll put the house number on it. As a verb: I'm waiting for them to post the dates for the concerts.
I went down to the post office to deliver my envolope.
It is a great folly to post grammar questions in the science section. =)
If I had the nerve I'd probably just post this as the answer.