Learn Swedish: Vägen är hal idag. - The road is slippery today.

You can use så to link this sentence to a second clause that shows the result of the slippery road. Because så is a coordinating conjunction, the word order in the new clause stays normal (Subject + Verb). For example: Vägen är hal idag, så jag kör långsamt (The road is slippery today, so I am driving slowly).

Why is the word for slippery hal here, and not halt?

Adjectives in Swedish change to match the gender of the noun they describe. Because väg is an en-word (en väg), the adjective takes its base form, hal. If you were describing an ett-word like ett golv (a floor), you would add a -t and say: Golvet är halt idag.

How does the word Vägen get its meaning of "The road"?

In Swedish, the definite article (the word for "the") is usually added as a suffix to the end of the noun rather than being a separate word in front. Starting with en väg (a road), you move that en to the end of the word to get vägen (the road).

Is idag always written as one word?

You will see "today" written both as one word (idag) and as two words (i dag). Both are perfectly correct in modern Swedish, though writing it as a single word is extremely common in everyday text.