Learn Swedish: Fågeln flyger mot klippan. - The bird flies towards the cliff.

Mot emphasizes the direction or trajectory of the movement ("towards"), while till implies the final destination ("to"). By using mot, we focus on the bird's path in the direction of the cliff, but we don't necessarily know if it actually reaches or lands on it.

Could mot also mean that the bird is crashing "against" the cliff?

Yes, mot can mean both "towards" and "against" depending on the context. With a continuous motion verb like flyger, it usually means "towards". If you wanted to clearly say it crashed against the cliff, you would use a verb of impact, like kraschar mot klippan.

Is en klippa the only word for "rock" in Swedish?

En klippa specifically refers to a cliff, a crag, or a large bedrock formation. If you are talking about a smaller, loose rock or stone that you could pick up or throw, you would use en sten.

What is the plural of fågeln (the bird) again?

The base word is en fågel (a bird). Because it ends in "-el", it drops the "e" when it becomes plural: fåglar (birds) and fåglarna (the birds).