Breakdown of Das Motorrad ist schneller, wenn der Verkehr schlecht ist.
sein
to be
schnell
fast, quickly
schlecht
bad
wenn
if / when (conditional, not a question word)
Questions & Answers about Das Motorrad ist schneller, wenn der Verkehr schlecht ist.
How do we form the comparative word schneller here?
We take the basic adjective schnell (fast) and add -er to mean faster. Because it is used after the verb ist rather than right before a noun, it does not take any extra adjective endings.
Why is the second ist at the very end of the sentence?
The word wenn (when/if) starts a subordinate clause. In German, these connecting words always kick the conjugated verb (here, ist) to the very end of that clause.
Does wenn mean when or if?
It can mean both! German uses wenn for both when (in the present or future) and if (conditions). In this sentence, both translations work perfectly.
Could we use als instead of wenn for when here?
No. The word als is only used for when when talking about a single event in the past (for example, when I was a child). For present, future, or repeating situations, you always use wenn.