"It rains at night."
I'm a bit confused, a lot of times I see sentences begin with time expressions folliwed by "ha". E.g Kyou ha kumori desu.. why is it different here?
The use of the particle は with a subject or topic generally means "as for /in regards to". Here, the particle isn't needed since it's a blanket statement. "it rains at night" doesn't need the extra emphasis. よるは雨がふります would be more like saying "as for night-time, it rains" (ex: if you were comparing weather in different times of day)
It isn't needed here, but can it still be used and mean the same thing (ignoring emphasis)?
I don't see why including は would mark it wrong when Duo always uses は in every other example this lesson.
雨 is just a noun, unlike in English where it is also a verb. 降る (ふる), a verb meaning to precipitate; to fall is needed to express that it is raining, or snowing, etc. The sentence is literally, "rain is falling at night."
This is more like what you'd say after looking at a weather report. This roughly translates to "It's gonna rain at night." What we require here is "It rains at night" which is よる雨がふります
Because that's slightly different from what's being asked. "Ame desu" was previously presented in Duolingo as "it's rainy", so your sentence would translate as "it's rainy at night".
Very subtle difference.
I believe you sentence would be closer to ~the night is rainy~ according to previous exercises.
Can someone explain the function of が here? like I generally understand it's function but i'm confused how this helps the verb phrase work...not even sure if i'm asking the right question
It marks the noun "rain" as being the (non-topic) subject of the sentence. In English, there is a verb "to rain", but in Japanese we have to say that "rain falls".
It's not really simple. In English, "rain" is both a noun (raindrops), and a verb (to rain). In Japanese, it's only a noun. "The rain is falling" is the correct sentence. Thus, the subject of "the falling" is the rain (雨). In other sentences, that same subject is the snow.