Breakdown of Der Affe ist nicht so schwer wie der Bär.
sein
to be
nicht
not
schwer
heavy / severe, serious
so
so, such (intensifier)
Questions & Answers about Der Affe ist nicht so schwer wie der Bär.
Why do we use wie here instead of als?
When you compare things using the pattern "as ... as", you use so ... wie. You only use als when one thing is strictly more or less than the other, like "heavier than" (schwerer als). Even though this sentence is negative ("not as heavy as"), it still uses the basic so ... wie equality structure.
Why is it der Bär at the end, and not an object case like den Bären?
When you compare two things using wie or als, the second noun takes the same case as the first one. Since der Affe is the subject of the sentence (nominative case), der Bär must also be in the nominative case.
Where exactly does the nicht go in a negative comparison?
The nicht goes directly before the so. Just like in English ("not as heavy as"), the German structure is always nicht so followed by the adjective, and then wie.
I have seen schwer used to mean "difficult". How do I know it means "heavy" here?
The word schwer can mean both "heavy" and "difficult", depending on the context. Since we are comparing the physical traits of an animal (a monkey) and another animal (a bear), "heavy" is the only meaning that makes logical sense here.