This lesson had me confused, as it's the first time I had seen the verb "devoir" by itself.
After a bit of internet sleuthing, I have learned that when devoir is not followed by another verb in infinitive form, it takes on the literal meaning "owes." However, if it is followed by a verb in infinitive form, it takes on the literal meaning "must."
Please, someone, correct me if I'm wrong.
Think of it as "have to eat", if that helps!
The rule, though, is that if you have two or more verbs (and it's not a composed tense like passé composé), you conjugate the first one and the rest are in the infinite. We largely do this in English, too, with "must" being an exception. I want to eat, I have to go, etc.
True story which I had forgotten about until now. I had this French guy giving me private French lessons. Afterwards when I wanted to pay him, he said that instead he wanted me to buy him two chickens. He knew of a farmer who sold chickens, so off we went, and I bought him two chickens which he kept in his back yard because he wanted fresh eggs. So, indeed, I did owe him a chicken... well, two chickens.
This is all so hilarious. It really has brightened my day! I'm still laughing at the "chicken currency" funnies. LOLOLOL Not making fun of the beautiful French language...just making light of what is difficult (and continuous) verbiage. One wonders why Duo continues to use "he/she/we/you owe(s) a chicken" rather than at least some of the times, perhaps saying that someone owes a euro, a meal, a favor, a debt or a ticket, etc. We love the French language and French speaking people!!
This sentence is useful for the laughter that it has provided us, and for the opportunity for us to exchange cultural experiences. This sentence is useful because it teaches us one of the ways that sentences can be constructed in French. This sentence is useful because it teaches one way to use the verb "devoir" and it reminds us that second person singular present tense for "devoir" is "dois". This sentence is useful because it teaches us that "poulet" means "chicken"
I don't know if this makes enough sense to help anyone else, but I've started to think of the English word "obligation" when i read "doire." [ERROR! See Sitesurf's correction; I should have written "devoir."] It also connotes these two senses of something one must do or give.