Nouns are formed by adding the ending o to the stem.
E.g.: domo – house, amiko – friend, arbo – tree, birdo – bird, teo – tea, tago – day, radio – radio, Eŭropo – Europe, tablo – table, biero – beer, papero – paper, bildkarto – postcard

Nouns distinguish number and case.

The final o may be dropped and replaced by an apostrophe. The stress is not affected. It is impossible to drop the noun ending if it is followed by plural or accusative ending.
E.g.: mia amik’ – my friend

Proper names can be classified into three groups – fully assimilated, partly assimilated and original.
The form of fully assimilated names was transcribed to the Esperanto alphabet, has Esperanto pronunciation and follows Esperanto grammatical rules (they have the o ending).
Jakobo – James, Paŭlo – Paul, Ĝenevo – Geneva, Eŭropo – Europe, Javo – Java, Nov-Zelando – New Zealand, Maro Ruĝa – Red Sea, Prago – Prague, Ŝekspiro – Shakespeare

Female proper names are formed the same way (Lukrecio – Lucretia, Mario – Maria) or are created from male names by the suffix in (Paŭlino – Pauline, Juliino – Julia, Mariino – Maria). However, today the tendency is to keep the name in its original form as much as possible. The names are often without an ending (Elizabet – Elisabeth) or with the ending a, which is normally used for adjectives, is used: (Eva, Johana – Joan, Marta).

The partially assimilated names use Esperanto alphabet (with or without Esperanto pronunciation) but do not have noun ending and the non-assimilated names keep their original form:
Beijing, Elizabeth, Eva, Allah, Nelahozeves, Praha, Goethe, Fuĵijama, Gorbaĉov, Shakespeare.

There is no no problem with assimilated names – they are declined as any other Esperanto word. If the unassimilated name ends with a vowel (pronounced), the accusative ending n is simply added to it (often preceded by a hyphen to facilitate understanding): Dante-n, Evan, Anna-n, Brno-n, Bordeaux-n. If the name ends with a (pronounced) consonant, the noun ending is added: Bill-on Clinton-on, Lebanonon.
Proper names are normally only in singular. However, there are few exceptions: Andoj – Andes mountains, Filipinoj – Filipines, la Burbonoj – Bourbons.

The basic rules for capitalization are the same as in most other languages – the proper names of persons, towns, rivers, countries, continents, books, etc are capitalized. It is common to also capitalise the names of months and nations. For the rest of the rules, see PAG§39.
Petro – Peter, Napoleono, Clinton, Eŭropo – Europe, Kanado – Canada, Pasko – Easter, Dio – God, Allah, la Biblio – Bible, Plena Ilustrinta Vortaro – The Full Illustrated Dictionary, Junio – June, angloj or Angloj – Englishmen, etc.