Breakdown of W przyszły weekend będę odpoczywał.
być
to be
w
in / on (a day)
odpoczywać
to rest
weekend
the weekend
Questions & Answers about W przyszły weekend będę odpoczywał.
Why do we use odpoczywał (which looks like a past tense word) after będę?
This is one of the two ways to form the future imperfective tense in Polish! You use the future form of the verb "to be" (będę, będziesz, etc.) plus the "l-participle" of the main verb. This participle looks exactly the same as the third-person past tense form (he/she/it rested).
Does the ending of odpoczywał change depending on who is speaking?
Yes. Because it uses the l-participle, this future tense form reveals the gender of the speaker. Będę odpoczywał is said by a man. A woman would say będę odpoczywała.
Could I just use the infinitive here and say będę odpoczywać instead?
Absolutely. Polish gives you a choice for the future imperfective: będę + l-participle (odpoczywał/odpoczywała) OR będę + infinitive (odpoczywać). Both mean exactly the same thing, but the l-participle version is very frequently used by native speakers, so you need to recognize it.
Why didn't przyszły weekend change its ending after the preposition w?
When talking about days of the week or a weekend, Polish uses the preposition w plus the accusative case. Because weekend is a masculine inanimate noun, its accusative form happens to look exactly the same as its basic dictionary (nominative) form.