Capital and lower case letters in Spanish

There are parallels and important differences in the conventions regarding capitalization in Spanish and English.

Proper names in both languages take a capital, for example geographical names:

Barcelona, Madrid, Londres, París, Italia, Andalucía, Canarias
el Nilo – the Nile, el Ebro – the Ebro, el Támesis – the Thames, la Sena – the Seine

But whereas the names of countries in both languages take a capital letter, the names of their inhabitants, their language and adjectives derived from them all take lower case initial letters in Spanish:

un francésa Frenchman
una francesaa Frenchwoman
los francesesthe French
el francésFrench (the language)
francés, francesaFrench (the adjective: un futbolista francés, a French fooball-player; a French word, una palabra francesa)
franceses, francesasFrench (plural adjective futbolistas franceses, palabras francesas)

Other nouns and adjectives, which in English would be spelt with a capital, take a small letter in Spanish:

adjectives and nouns derived from place names:
madrileño – ñaderived from Madrid
barcelonés – lonesaderived from Barcelona
limeño – ñaderived from Lima
neoyorquino – naderived from Nueva York
londinensederived from Londres (London)
adjectives and nouns derived from names of founders of movements, schools of thought, etc.
cristiano –naChristian
Names of days of the week and months take a small letter in Spanish.
lunes, martesMonday, Tuesday
marzo, abrilMarch, April
Personal names, including nicknames, take a capital letter:
Pedro – Peter,
Juan – John,
Juana – Joan,
Cristina – Christine,
Pepe – Joe (roughly)
Note that titles of political post-holders are spelled with small letters:
el canciller alemán, Gerhard Schröderthe German Chancellor
el primer ministro chinothe Chinese Prime Minister

It is by no means unusual to see these conventions broken, especially in advertising, but it is not safe to use such texts as models for your writing. Frequently advertising copy-writers are aiming to produce subtle effects, which will just appear to be a mistake in a different context.

Spanish language resources