1 .Use “damare” as a universal “shut up” command.
For ordinary “shut up” usage, try this short phrase.
The pronunciation is “dah-mah-ray.” “Dah” and “mah” both more or less rhyme with “raw“.
Keep in mind that the r sound utilized here is rapid and light, similar to a Spanish r.
The r is pronounced with a slight tongue flick, similar to how an English d or the two ts in the word “butter” are pronounced.
2. To speak from a position of authority, say “damarinasai.”
Use this option if you want to advise someone to stop talking in a way that comes across as if you have authority over them (like a boss or a police officer).
“Dah-mah-ree-nah-sigh” is how to say it. The the first three syllables are just like “damare,” only with a long e sound (as in “tea”) at the end.
The last “sigh” is pronounced like the English term, and “nah” also rhymes with “raw.” The approximate meaning here is “silence!”
3. You can use the semi-rude expression “yakamash” to say “you’re being too loud.”
Despite its literal meaning of “noisy,” this expression implies that the subject of your conversation should be quiet.
The pronunciation is “yah-kah-mah-shee” (basically how its English form is spelled).
One thing to be aware of is the “shee” at the end of words; in Japanese, this long vowel is held nearly twice as long as a regular vowel.
The final word of this sentence is held out for something like “yakamasheee,” which can give it an almost “whining” tone to an English ear. 
4. Or you might say “urusai.”
The connotation of this phrase is quite close to that of yakamash.
The pronunciation is “ooh-roo-sigh.”
Keep in mind that the lips do not advance for the long u sound in Japanese.
 As a result, the vowel sounds in “ooh” and “roo” should be roughly in the middle of “oo” in “root” and “u” in “rut.” It might take some practice to do this.
5. For an irate “be silent,” say “shizuka ni shiro yo!”
Basically, using this phrasing to request quiet is abrupt and unpleasant.
If you’ve politely requested someone to remain quiet before and received no reaction, this is a decent option.
Say “shee-zoo-kah knee shee-roh yo” after this. Remind yourself that the lips do not move forward when making the Japanese u sound.