Learn Swedish: På måndag ska vi träffa chefen. - On Monday we will meet the boss.

Because Swedish uses the V2 rule, meaning the verb is almost always the second piece of information in a sentence. Since the sentence starts with the time phrase På måndag, the verb ska must come immediately after it, pushing the subject vi to the third spot.

Does På måndag mean this coming Monday, or Mondays in general?

In this sentence, it means this coming Monday because the verb ska shows we are talking about the future. If you wanted to say 'On Mondays we meet the boss' as a weekly routine, you would use the plural form and say På måndagar instead.

Why is the verb träffa in its basic dictionary form?

Because of the helper verb ska (will / are going to). Just like in English, when you use a helper verb, the main verb that follows it stays in its infinitive (basic) form. So it is ska träffa, never ska träffar.

How does the word chefen mean 'the boss'?

In Swedish, 'the' isn't a separate word that comes before the noun. Instead, it is added to the end of the word. The word for 'a boss' is en chef. To say 'the boss', you add -en to the end, making it chefen.