بنت Bint vs bint-un
So in my book it says that most nouns and adjectives in MSA are in the nominative case, sorry I don't know what it's called in Arabic, but basically you just pronounce an "un" at the end because there's a wee symbol. But it also says that it's basically never pronounced. How true is this?Just found out the little symbol I'm referring to is this: تنوين الضم

Question

بنت Bint vs bint-un
So in my book it says that most nouns and adjectives in MSA are in the nominative case, sorry I don't know what it's called in Arabic, but basically you just pronounce an "un" at the end because there's a wee symbol. But it also says that it's basically never pronounced. How true is this?Just found out the little symbol I'm referring to is this:   تنوين الضم

Answer

There is three types of tanween all of it is pronounced. This may be help you about tanween. 
https://ar.m.wikipedia.org/wiki/تنوين

Answer

my adice to you miss or Mr.Spangola is not to rely on arabs as a source of knowledge in Standard Arabic , the sad fact that we make a huge a amount of mistakes due to the reason that I already talked about , so you can rely on some scholars of Arabic or "Mashaykh" of religion they usually speak perfect Arabic not Perfect but some of them really don't make mistakes because they have studied Arabic as a part of their religious studies deeply !

I can give you some resources or some tips if you want futher informations or tips to master Arabic , don't hesitate to ask please !

thanks for reading and for the nice question .. !

Answer

well , first ,I would like to thank you for this smart question  , before I answer your question I would like to ask for the source ? which book do you use for grammar? it's very important to carfully choose the matrial when learning Arabic "Standard" because you can get wrong or misleading information !

firstly;  the nominative case in Arabic called "Raf'"  الرفع .

secondly : this thing at the end or this sound called "Tanwin" means there's "N" sound but you don't write it you just pronounce it , so you write "بنت" but you pronounce it " بنتون" the second one is  incorrect of course in writing ; so inorder to show that there's a sound of tanwin means a "+NOUN LETTER"  we write this symbol at the end we write double "dhuma" it's called "ضمة"

and To answer the proclamation of your textbook , I would agree with it partially not intirely , How?

yes most of Arabic speakers native or non natives don't pronounce this sound , but is that correct? yeah sometimes you don't have to pronounce it in one case only , when you stop for example you're reading and you want to breath so you need to stop at the word you don't say "Bintun' rather "bint" ..only in this case it's allowed to not ponounce this sound ..but in all cases you need to pronounce it if you want to speak Arabic accurately ..

now the question ; why do the Arabic speakers neglect this sound? there're many reasons for that :

firstly , you need to bear in mind that Arabs speak dialect as native tongue not modern standard Arabic , this is a fact in our daily life we speak in the local dialect which can be far away from the Standard version , and therefore , Arabs do not speak accurately , I can say that it's wrong , unfortanetly it's a common mistake even in the media

second reason ; sometimes the speaker is not sure about the ending of the word wether is it Nominative , Dative ..etc so he rather prefer to not fall in mistake by using this trick especially in formal speech in the news ..to be continued !