Wait, I just noticed Duolingo spells woman אישה instead of אשה. Why? Wouldn't אישה... look like איש.ה? Her man? Wait a minute "אשה" and "אישה" sound the same? Actually how strange is it nowadays to use the possessive suffix on the noun? Like, if I were to go to Israel speaking like that, would it be like going to Britain and speaking "Shakespeare?" Or is it more like going to Italy speaking Latin?
There are two different systems of spelling in Hebrew: ktiv haser and ktiv maleh. In Ktiv Haser, which is the original historical Hebrew spelling, woman would be אשה. Also, in vocalized texts (with niqqud, or pointilized vowels), you would generally use that spelling. But in modern Hebrew usually uses ktiv maleh, in which it's common to add the extra yod to show that there is the "ee" vowel sound there in unvocalized texts. In ktiv maleh, the matris lectionis letters, yod, aleph, hei, and vav, to represent vowels in certain places to clarify pronunciation
Since there is no punctuation in everyday Hebrew, it's very common to add vowels so people would understand more easily. Another example would be writing "כוח" instead of "כח" which means force.
And no, it's nothing like that. I guess that the younger generation doesn't speak like that and they would probably laugh if they hear someone young speaks like that, but they would still understand you. The older generation (even people in their 40's or 50's) still speaks like that.
On a second thought I guess that this question is much more complicated to answer. It really depends on which word we are talking about and also on the population.
For example for the word "אח" (brother) you would probably use thee possessive ending and say "אחי" or "אחיך". You are right that we mostly don't use it, but my grandparents still do and also many other older people because they were taught proper Hebrew and I guess it has just changed with time for some reason.
I would definitely not compare it to Shakespearian and modern English, or Latin and Italian since modern Hebrew hasn't existed for that long.
Are they mainly kinship terms that still use that then? Brother, sister, cousin? What about things like places? Houses, cities, regions, countries?
And about how different would they be? Taking the language written in the book of Genesis and comparing that to the streets of Tel Aviv. Maybe say, Scottish highlands and New Yorker, or... I don't know I guess I want some kind of comparison. :P
A lot of these words do get the possessive ending, but I'm afraid that if you are looking for a specific rule of when to use it, there is no any :(
If you come to Israel, maybe you'd rather stick to saying "שלי/שלך/שלו" etc at the beginning at least, and then you'd just get when to use the endings when you hear other people talk. Also, just clarifying again, using the suffixes is grammatically correct and people will understand, it's only the way we talk that is different.
Biblical Hebrew and spoken modern Hebrew (especially in Tel Aviv!) would be light years away from each other. Apart from a couple of words here and there (which are probably not even pronounced the same) you would probably not hear much similarities. I think it's something like comparing old Nord and modern Norwegian, or maybe old English and modern English (but it's also not exactly the same).