"May I have a coffee and a slice of bread and butter, please?"
Translation:Puis-je avoir un café et une tartine, s'il te plaît ?
"je" is connected to "puis" by a hyphen, so the form "puis-je avoir" remains
The uninverted form of that is "je puis avoir". in dual verb constructions, only the first verb is conjugated and the succeeding ones either remains an infinitive or become a participle.
The conjugation of "avoir" for "je" is "ai", you cannot say "j'avoir" but "j'ai"
That « tartine » is giving me a hard time, idk what to translate it for, I once used "(a) slice of bread", and was marked correct, then I used "(a) slice of bread and butter" on the next question and was marked correct. And now on this thing I used "(a) slice of bread" and now it was wrong. Hehehe seems like I'm not good at guessing, I guess.
(Good thing I haven't eaten a tartine when I went to Nantes, I wanted to kill myself out of shame for eating almost every French food the wrong way. I don't even know there is a wrong way.)
The FR "tartine" is a slice of bread that has something spread on it. It may be butter (unless you specify else), or jam, or some other spread. Why? The verb "tartiner" means "to spread". So in general, you can think of "une tartine" as a slice of bread with butter on it, a staple at grandma's house when les petits-enfants come for a visit.
On second thought, I think you might not understand verb- verb constructions.
Several verbs such as devoir, pouvoir, vouloir, and savoir, are used this way. The first verb is conjugated, and the second is an infinitive.
Je peux avoir (I am able to have) Il veut aller à chez nous. (He wants to go to our house.) Tu dois payer (You have to pay)
Not always. See this link regarding the exception for when je is inverted.