Spain
noun: Spaniard(s)
adjective: Spanish
Sri Lanka
noun: Sri Lankan(s)
adjective: Sri Lankan
Sudan
noun: Sudanese (singular and plural)
adjective: Sudanese
Suriname
noun: Surinamer(s)
adjective: Surinamese
Swaziland
noun: Swazi(s)
adjective: Swazi
Sweden
noun: Swede(s)
adjective: Swedish
Switzerland
noun: Swiss (singular and plural)
adjective: Swiss
Syria
noun: Syrian(s)
adjective: Syrian
Taiwan
noun: Taiwan (singular and plural)
note: example - he or she is from Taiwan; they are from Taiwan
adjective: Taiwan
Tajikistan
noun: Tajikistani(s)
adjective: Tajikistani