By convention, names of human languages are written in lowercase in Finnish: suomi, italia, esperanto. Names of computer “languages” are capitalized, e.g. C, Perl, Java.
Finnish often has the same name for a language and for country, just with the spelling difference that that the country name is capitalized, the language name is not. Examples: suomi – Suomi (Finnish – Finland), ruotsi – Ruotsi (Swedish – Sweden), italia – Italia (Italian – Italy), englanti – Englanti (English – England).
When needed, the language name can be clarified by using it as a genitive attribute before the noun kieli (language), e.g. suomen kieli. This principle extends to language names that do not match a country name, e.g. kurdi – kurdin kieli. Adjectives for languages are based on such longer expressions, e.g. suomenkielinen (Finnish, Finnish-language).
A country name can sometimes be clarified by using a compound where the first part is the name in the genitive and the second part is maa (country), e.g. Suomenmaa = Suomi, Venäjänmaa = Venäjä (Russia), Ranskanmaa = Ranska (France), Tšekinmaa = Tšekki (Czech). However, such longer names are somewhat poetic, and they cannot be formed from most names. If really needed, the corresponding open compound could be used, e.g. Italian maa = Italia.
The suffix lAinen is used to derive words from country names for use both as an adjective and as a noun. In noun usage, the word denotes an inhabitant of the country or a member of the nation. In adjective usage, it means something belonging to or typical of the country or the nation. Thus, for example, saksalainen, derived from Saksa (Germany), can mean a German person (either as “a person living in Germany” or as “a member of the German nation”) or “German” as an adjective. However, saksalainen does not normally refer to language; for that, saksankielinen is used, e.g. saksankielinen kirja (a book in German).
The derivations suomalainen and ruotsalainen have an irregular vowel change from i to a in the base word. Another irregularity is venäläinen (Russian) from Venäjä.
Most places in Finland have only a Finnish name, but many places also have a Swedish name, e.g. “Åbo” for Turku, “Vanda” for Vantaa. In Lapland, places also have names in Sámi languages.
When referring to places in Finland in foreign-language texts, it can be difficult to decide whether Swedish names should be used for places in an area where the majority speaks Swedish. At least for Åland (Finnish Ahvenanmaa) and places there, Swedish names can be preferred in languages other than Finnish, since Swedish is the only official language in Åland.