Mono- means "one" in Greek

There are several words in English which start with mono-. Mono- is a Greek prefix which means "one."

1 monosyllables 單音節 （名詞）, monosyllabic 單音節 （形容詞）
Most Chinese characters （漢字）are monosyllabic

2 monolingual people only speak one (mono-) language (lingu-)

3 A monarchy is a country ruled by a monarch. A monarch is a king or a queen. Denmark is a monarchy. A monarch often wears a "hat" like this one. This crown belongs to the Queen of Denmark (丹麥). (Mono --> Mon-) Mon- = one; arch = rule

Danish crown -- Sunfox's photostream (Flickr)

The president of the US should never ever (絕對從來都不可以) bow to any monarch. Barack Obama made history by bowing to the King of Saudi Arabia (YouTube video) at a meeting of world leaders. Look carefully: the President of France seems to be laughing at the President of the US. Thinking people are not proud of this leader.

President Obama (US) is bowing to the Saudi king and kissing his hand. Does the king respect Obama? What does President Sarkozy (France) think?

4 "Mono" is the short name for infectious mononucleosis (傳染性單核白血球增多症), the "kissing disease" (有接吻熱、接吻病). You can get the EB virus (人類泡疹病毒) by kissing somebody who got sick a few weeks ago.

Main_symptoms_of_Infectious_mononucleosis ( Wikimedia Commons)

People who have the EB virus (人類疱疹病毒第四型) may get systemic lupus erythematosus (紅斑性狼瘡) and various cancers (癌症) when they are older.

Lupus_facial_rash (紅斑性狼瘡) (Wikimedia Commons)

Remember, even "nice" people may have the EB virus.  
Be careful who you kiss!

5 Monopoly ~ "One seller" (壟斷, 獨占: only one company sells a product, so they can make the price very high). In Taiwan, only children play Monopoly (大富翁). In the US, many adults like to play this game.  

Monopoly -- A.A.'s photostream (Flickr).jpg