Learn Swedish: Varför är mannen arg?

Because the sentence starts with the question word varför (why), the verb must come next! Swedish has a strict "verb-second" rule. So, the verb är (is) takes the second spot, and the subject mannen (the man) gets pushed to the third spot.

Is there an easy way to remember that varför means "why"?

Varför is built from the words var (where/what) and för (for). It literally translates to "where-for". If you think of the old English word "wherefore" (which also means "why"), or the common phrase "what for?", it makes perfect sense!

Why is "the man" written as mannen?

In Swedish, you don't use a separate word for "the". Instead, you attach it to the end of the noun. The basic word is en man (a man). To say "the man", you add -en to the end. Notice that the n doubles to become mannen; this spelling change keeps the "a" vowel sound short.

Why is the adjective arg in this specific form?

Swedish adjectives change to match the noun they describe. Because mannen is a singular "en-word" (from en man), the adjective stays in its basic dictionary form: arg. If we were talking about a plural noun like "the men" (männen), it would change to arga.