1-one        
2-two
3-three
4-four
5-five
6-six
7-seven
8-eigth
9-nine
10-ten
11-eleven
12-twoelve
13-thirteen
14-fourteen
15-fifteen
16-sixteen
17-seventeen
18-eihteen
19-nineteen
20-twenty





20 coutries and nationalities :

China-Chinese
Cuba-Cuban
Columbia-Colombian
Costa Rica-Costa Rican
France-French
Uruguay-Uruguayan
Afghanistan-Afghan
Brazil-Brazilian
Bolivia-Bolivian
Germany-German
Japan-Japanese
Mexico-Mexican
Venezuela-Venezuelan
Syria-Syrian
Italy-Italian
Spain-Spanish
Russia-Russian
Peru-Peruvian
Paraguay-Paraguayan
Panama-Panamanian