Breakdown of Что вы делаете в понедельник?
вы
you (plural or formal)
что
what
делать
to do
в
on / during (a time period)
Questions & Answers about Что вы делаете в понедельник?
Why do we use в here if it usually means "in"? English uses "on" for days of the week.
Prepositions rarely translate perfectly word-for-word between languages. In Russian, the rule for saying "on a certain day of the week" is to use the preposition в (or во) followed by the Accusative case. It is best to memorize в + day of the week as a set pattern.
The lesson says to use the Accusative case for days of the week. Why hasn't the word понедельник changed its ending?
Понедельник is actually in the Accusative case here! Because it is a masculine, inanimate noun (a concept, not a living person or animal), its Accusative form is exactly the same as its Nominative (dictionary) form. It only looks like it hasn't changed.
The translation says "are doing", which implies future plans. Can the present tense verb делаете be used for the future?
Yes. Just like in English ("What are you doing on Monday?"), Russian frequently uses the present tense to talk about definite or scheduled plans in the near future. Also, keep in mind that Russian only has one present tense, so делаете covers both "you do" and "you are doing".
How should I pronounce в понедельник? Do I pause between the words?
You should not pause. Short prepositions like в merge with the following word and are pronounced as if they are a single unit. Because the letter п is a voiceless consonant, the в changes its sound to an "f". You should pronounce it together as "fpa-nee-dyel'-neek".