Learn Portuguese (Portugal): Eu não sou português.

In Portuguese, making a sentence negative is very straightforward. You just place não directly before the verb. The sentence literally translates to 'I not am Portuguese'.

Can I drop the eu and just say não sou português?

Yes, you can! Because the verb form sou means 'I am', the pronoun eu is optional. Portuguese speakers frequently drop subject pronouns unless they want to add special emphasis, like saying 'I am not Portuguese (but he is)'.

If a woman is saying this sentence, does anything change?

Yes, she would say Eu não sou portuguesa. Words for nationalities change to match the gender of the person they describe. To make português feminine, you add an 'a' at the end and remove the accent mark over the 'e'.

Why isn't the word português capitalized?

Unlike in English, words for nationalities and languages are written with lowercase letters in Portuguese unless they appear at the very beginning of a sentence.