Voiceless palato-alveolar sibilant

IALA = International Auxiliary Latin Alphabet

IALA: q
IPA: Greek letter esh
X-SAMPA: S

Monograph
Hungarian: s
Maltese, Portuguese [partially] and several Amerindian languages: x

Monograph with diacritics
Czech and others: s-caron
Romanian: s-comma
Turkish: s-cedille
Esperanto: s-circumflex

Digraph
English: sh
Polish: sz
Italian: sc (depending on followig vowel)
French: ch
Malay/Indonesian: sy
Swedish [close] : sk (depending on followig vowel), sj

Trigraph
German: sch