Ik kan fietsen.
English: I can ride a bike.
In Dutch, 'kunnen' and 'willen' are modal verbs. They help you talk about ability (can) and desire (want). You use them with another verb, which stays in its basic form.
Use 'kunnen' to say you are able to do something or that something is possible. Use 'willen' to say you want something or want to do something.
Ik kan fietsen.
English: I can ride a bike.
Wil jij koffie?
English: Do you want coffee?
Wij kunnen samen werken.
English: We can work together.
Hij wil naar huis gaan.
English: He wants to go home.
Kunnen jullie helpen?
English: Can you (all) help?