A nationality is an adjective and agrees with the person: add -e for a woman, -s for a plural. That final -e is what makes the preceding consonant audible - français sounds like "fran-say" but française like "fran-sez". Nationalities are lower case as adjectives, capitalised as nouns.
Examples
- Je suis anglais, de Manchester.
- I'm English, from Manchester.
- Elle est allemande et il est espagnol.
- She is German and he is Spanish.
- Nous sommes canadiens.
- We are Canadian.
The mistake to avoid
An adjective already ending in -e does not add another: suisse stays suisse for both.
Where this fits in
Greetings & introductions, French A1: Say hello, give your name, ask someone else's, and where they're from.