There is a two-letter word in English that perhaps has more meanings than any other two-letter word,  and that word is 'UP.'  It is listed in the dictionary as being used as an [adv], [prep], [adj], [n] or [v]. 

It's easy to understand UP, meaning toward the sky or at the top of the list, but when we awaken in the morning,
 why do we wake UP 
At a meeting, why does a topic come UP ? Why do we speak UP, and why are the officers UP
 for election and why is it UP to the secretary to write
 UP  a report? We call UP our friends and we use it to brighten UP a room, polish UP  the silver, we warm UP the leftovers and clean UP the kitchen. We lock UP the house and some guys fix UP the old car.  
At other times the little word has a real special meaning. People stir UP trouble, line UP for tickets, work UP an appetite, and think UP  excuses.  

To be dressed is one thing but to be dressed UP is special.

And this up is confusing:  
A drain must be opened UP
  because it is stopped   UP.

We open 
UP a store in the morning but we close it UP at night.   We seem to be pretty mixed UPabout UP !  

To be knowledgeable about the proper uses of UP , look the word UP
  in the dictionary. In a desk-sized dictionary, it takes   UP almost 1/4 of the page and can add  UP to about thirty definitions  

If you are UP
  to it, you might try building UP a list of the many ways UP is used. It will take UP a lot of your time,
  but if you don't give UP, you may wind UP with a hundred or more.  

When it threatens to rain, we say it is clouding UP . When the sun comes out we say it is clearing UP. When it rains, it wets
 UP the earth. When it does not rain for awhile, things dry UP.  

One could go on & on, but I'll wrap it 
UP , for now  ........my time is UP , so time to shut UP