The French terminations -ois / ais serve as both the singular and plural masculine; adding 'e' (-oise / aise) makes them singular feminine; 'es' (-oises / aises) makes them plural feminine.
The Spanish termination "-o" usually denotes the masculine and is normally changed to feminine by dropping the "-o" and adding "-a".
Many place-name adjectives and many demonyms also refer to various other things, sometimes with and sometimes without one or more additional words.
Note: Many of these adjectivals and demonyms are not used in English as frequently as their counterparts in other languages.
A common practice is to use a city's name as if it were an adjective, as in "Vienna Philharmonic Orchestra", "Melbourne suburbs", etc.