Learn Portuguese (Portugal): Eu não tenho catorze carros!

Ter is an irregular verb, meaning it doesn't follow the normal pattern for verbs ending in -er. For "I have" (eu), the form is tenho. Because it is irregular, you just have to memorize this one!

Can I leave out the word eu and just say Não tenho catorze carros!?

Yes! In Portuguese, the verb ending usually tells you who is doing the action. Since tenho is only ever used for "I have", saying the eu (I) is completely optional. Including it just adds a bit of emphasis.

In English we say "I do not have", but here there is no word for "do". Why?

Portuguese doesn't use helper words like "do" or "does" to make a negative sentence. You simply put não (not) directly before the verb. So, "I do not have" is just não tenho (literally "not I-have").

I've sometimes seen the number fourteen spelled as quatorze. Is catorze a typo?

Not a typo! Both catorze and quatorze are technically correct, but in European Portuguese, catorze is the standard and far more common spelling for the number fourteen.