"Ma'am, do you need a taxi?"
Translation:Señora, ¿necesita usted un taxi?
Because the sentence uses Ma'am (senora) (sorry no accents) you needed to use "necesita" - the 3rd person, formal you. "Necesitas" is the 2nd person, informal you.
Tú is used to say you to a friend, family member, someone your age or younger, someone you call by a first name or term of endearment, etc.
Usted is used to say you to an older person, a stranger, someone you call by their title and last name like a boss or professor, etc.
It all depends on what your relationship is with that person (familiar or formal).
In this sentence, since you are calling her ma'am, you are using the formal necesita usted.
also important to note that when using "Tú" you must use the "Tú" tense (estudias, hablas, quieres, etc.) and when using "Usted" you must use the "Él/Ella/Usted" tense (estudia, habla, quiere, etc.)
what is ud? duolingo:Señora, ud. necesita un taxi? Mine:senorita tu nesecita un taxi
"ud." is short-hand for "usted". when talking formally in spanish, you use the "él/ella/usted" tense which is "necesita" which you did, but you said "tú" instead of "usted", and tú is casual in spanish
the answer is "usted requiere" but I think the right is "usted quiere"
'requiere' maybe - it means require;
'quiere' maybe - it means want;
'necesita' is better for 'you need'
I don[t think that Duolingo has taught the word requiere yet. However it was in their correction.
Why is" tu nesecita una taxi" wrong? Reading it from the first answer to English is "need you a taxi" which the flipping of those words is confusing as well
"necesita" is the "él/ella/usted" form of necesitar, not the "tú" form which would be "necesitas". "tú necesitas un taxi" is correct spanish, but you use "usted" (and change verbs to its form) when it's formal. the "señora" here indicates that this is formal. not to say this is self-explanatory though, it isn't. not sure about the word order though, and whether "usted necesita un taxi" is as correct as "necesita usted un taxi".