Ufhg10, this is in the tips and notes, in "determiners"
"Impersonal Plural In this unit we also introduce what we call the "impersonal plural". At times you may come across plural forms of verbs in Hebrew that are not connected to a personal pronoun. For example, a "normal" sentence with a plural form of a verb would be:
They eat apples. - .הם אוכלים תפוחים But when you see a sentence like:
אוכלים תפוחים Does it mean "We eat", "They eat", or "You (all) eat"?
The answer is that it can be all of these and more! In fact, it is sometimes hard to translate this type of sentence into English without context. There are several options that can be considered:
One eats apples. (Can sound a bit old-fashioned nowadays.) You eat apples. (You as in "anybody" - can be confused for actual "you") We/They eat apples. (You have to know who is being spoken about, to know whether the speaker is including or excluding him/herself from the group) Apples are eaten. (At times using the passive can be the most elegant solution, but is not always an option) Polyglots should be able to find parallels with the ways in which many other languages create impersonal expressions: French: On mange les pommes. German: Man isst Äpfel. Spanish: Se comen manzanas/Uno come manzanas. Dutch: Men eet appel.
At times it can also have a suggestive tone. For example, if someone says מדברים עברית, it can be equivalent to "one speaks Hebrew", but can also mean something like "you should be speaking Hebrew!"."
You wrote: "There is no נו- so how do you know?" I'd like to add one thing to Teri's excellent reply.
The נו is the past tense ending for the pronoun we. This sentence is in present tense, where the plural ending ים includes the pronouns we, you and they (all that are masculine plural, that is - and that's usually the case for general sentences like this one.). Now you can properly apply what Teri quoted from "tips and notes."
Many seem to have problems with translating "shalom" as meaning "hello" or "hi". Shalom is a greeting when spoken to someone, hence the meaning hello. But it actually means "completeness", "soundness", "welfare" or "peace". So "Hello/hi" is actually a little unprecise. When used as a greeting, "Peace!", or "All good!" is a better translation.
My answer being...? And I’m not being sarcastic, but if your answer was “We say hello to be polite”, Duolingo doesn’t want an answer, it wants a translation.
Or maybe you didn’t put the word hello in quotation marks. That was a problem for a lot of other people here.