1. Down indicates movement from a higher place.       

Pattern: noun + verb + down + noun
The rocks rolled down the mountain.              

Typical verbs used before down:
come, fall, go, move, roll, run, slide, walk

2. Down means following the way of; along  

Pattern 1: noun + verb + down + noun

The old man went down the road on foot.

Typical verbs used before down:
come, drive, go, move, run, skate, walk 

Pattern 2: noun + verb + noun + down + noun
The boys rode their bikes down the street this morning.         

Typical verbs before down:
bring, carry, drive, move, pull, push, ride, take           

Typical nouns after down:
freeway, highway, path, road, sidewalk, street, turnpike                      

3. Down indicates destruction.                     

Pattern 1: noun + verb + down + noun
The intruder broke down the door.                  

 Typical verbs used before down:

 blow, break, bring, burn, cut, strike, take                     

Pattern 2: verb + noun + down
The intruder broke the door down.                  

4. Expression              

upside down—turned so that the bottom is on top
The cups go in the dishwasher upside down.             

5. Phrasal verbs                  

back down (intransitive)—retreat
The dog backed down when I called his name.           

calm down (separable)—soothe; tranquilize
We had to calm the children down after the excitement.          

close down (separable)—stop business activity, temporarily or permanently
We close the shop down at four o'clock every day.
They plan to close that business down for good.                                                        

come down with (nonseparable)—become sick
She missed the picnic because she came down with the flu.               

crack down on (nonseparable)—impose restrictions
The police are cracking down on street violence.                    

let down (separable)—disappoint
She let me down when she didn't help me with my party.      

look down on (nonseparable)—feel superior to
The older students tend to look down on the younger ones.               

mark down (separable)—lower in price
I bought this shirt after they marked it down to ten dollars.                 

put down (separable)—insult
She shouldn't go out with him; he puts her down all the time.            

run down (separable)—criticize negatively
She always runs her hometown down.            

shut down (separable)—turn off a computer; end a business
She worked all night and didn't shut her computer down until morning.
They shut that shop down two years ago.                                                                   

 turn down (separable)—reject
He got a job offer today but he is going to turn it down.         

write down (separable)—put on paper for future reference
She didn't know my phone number, so I wrote it down for her. 

Twitter