I speak Norwegian. She speak*s* Swedish. We sp*o*ke Danish.
Speak is an irregular verb. It has the -s and -ing endings, but 'speaked' would be wrong. Verbs which involve vowel changes (like spoke and spoken) are sometimes called strong verbs.
Adjectives describe objects, people or states.
The ball is red. There is a green ball.
Adverbs describe verbs. In English they often end in -ly. Adverbs often tell you how people do things.
He ran quickly.