Ability expressions

Choose a general or specific expression according to what you want to say. Kan inte is possible even when the practical obstacle is time or tiredness; hinner inte and orkar inte identify those obstacles more explicitly.

1. Skill or General Possibility: kan
Use kan for learned skills, capability, or practical possibility: Kan du komma i morgon? asks whether coming is possible.
Example: Jag kan tala svenska. (I can / know how to speak Swedish.)
Note: After kan, use the infinitive without att.

2. Physical or Mental Stamina: orkar
Use orkar when expressing whether you have the strength, energy, or mental endurance to do something.
Example: Jag kan göra det, men jag orkar inte. (I am capable of doing it, but I don't have the energy.)

3. Having Time: hinner
Use hinner when ability depends on time or scheduling.
Example: Hinner du äta lunch? (Do you have time to eat lunch?)

4. Courage: vågar
Use vågar for daring to act despite a perceived risk. Courage and practical ability are different: daring to try does not guarantee success.
Example: Hon vågar inte fråga. (She doesn't dare to ask.)

Overlapping Choices
Jag kan inte springa mer eftersom jag är så trött is grammatical. Jag orkar inte springa mer makes lack of stamina explicit. Similarly, Jag kan inte komma på festen för klockan är mycket gives a practical obstacle, while Jag hinner inte komma på festen specifically describes insufficient time.

After kan, use a bare infinitive: kan simma. Orka, hinna, and våga also occur with att in established usage; the bare-infinitive examples here are useful models, not a ban on the alternatives.