“Quiero”, “puedo”, “duermo”: verbs that change inside

Some very common verbs change a vowel INSIDE the word: querer gives quiero, poder gives puedo, pedir gives pido. The change happens in every person except nosotros and vosotros, which keep the original vowel: queremos, podemos, pedimos.

The usual slip. Conjugating them as regular verbs: quero, podo, pedo — the last one means something rather different.

Why it catches you out. English verbs change at the END and never in the middle, so a vowel that shifts inside the word has nothing in your language to hook onto. The shape is regular though: the change happens where the stress falls, which is why “nosotros” is exactly the person that escapes.