Sierra Leone
noun: Sierra Leonean(s)
adjective: Sierra Leonean
Singapore
noun: Singaporean(s)
adjective: Singapore
Slovakia
noun: Slovak(s)
adjective: Slovak
Slovenia
noun: Slovene(s)
adjective: Slovenian
Solomon Islands
noun: Solomon Islander(s)
adjective: Solomon Islander
Somalia
noun: Somali(s)
adjective: Somali
South Africa
noun: South African(s)
adjective: South African
Spain
noun: Spaniard(s)
adjective: Spanish
Sri Lanka
noun: Sri Lankan(s)
adjective: Sri Lankan
Sudan
noun: Sudanese (singular and plural)
adjective: Sudanese