Your explanation was given to me for years, by many, many different sources, and I struggled with it, because any Russian I hear with the letter "щ" doesn't sound anything like "sh+ch". I was always told that "щ" is a sound like "sh+ch", such as the sound when you say "fresh cheese", yet no russian I have ever heard with this letter sounds at all like that! Even when I asked a Ukranian friend of mine to say the two letters to me, it did not sound like this. The best explanation, I ever heard, is that "ш" is a sound made with the tongue further down away from the top teeth, whereas "щ" is a slightly hissier sound made with the tongue closer to the top teeth. This sounds exactly like all the Russian I have heard with the two letters "ш" and "щ". With that explanation, as a native English speaker, I would say that "щ" is actually the sound when I say "sh", and that "ш" is not a sound that I use in English. It is somewhere between 'щ' and the the sound "х" makes in Russian (like the word характер), or the german "ch" sound (like in the word "ich". Of course, this is also a sound not used in the way I speak English.
If you say женшчина then щ is the sound which is made when ш transforms to ч, that is when your tongue goes from Ш position to Ч position. "Х" sound is made with the middle part of one's palate (like relaxed К), while Ш Ч Щ are made with the frontal part near teeth (as well as English SH and CH).
If I hear it correctly and "sheep" and "ship" have different SH, the Щ is closer to that in "sheep" and farther from "ship".
Practicing the alphabet with Memrise is very helpful as well:
Btw, there is one more difference except the stress: when you see two identical letters together (like аННа, ваННа, стреСС, etc), you should pronounce them like Russians do.
In English people usually see "nodded", but say [noDid], not [noDDid].
In Russian the double letters usually are noticeable in pronouncation: [аН-На], [каС-Са]. Just make the [Н] (or [С] for касса) sound twice more long. Or 1,5–1,7 instead of twice =)
There are several versions of when a girl becomes a woman:
- When she begins to live with a man (in marriage or not).
- When she gives birth.
- When she reaches an age at which it is no longer possible to be called a girl. This varies. Some insist on calling themselves "девушка" being in their 30s or even 40s.
Among themselves, even elderly women can address a group of their peers as "девочки". This is funny :-)
Personally, I stopped thinking of myself as a girl after I became a mom. Девушка with a child is a nonsense for me :-) I was 30 at that time.
Imagine a situtation where you mentioned of Billy ( a woman) without specifying her gender but your friend called her a 'he' because she own a unisex name. So you would correct your friend saying 'btw, she is a woman.''. One could also imagine some cases in relation with gender fluidity etc.
My question was actually a hint that "Она женщина" is not redundant - just like "She is a woman" is not redundant, too :-)
By the way, if you were correcting your friend (like you described) in Russian, you'd rather say "это женщина" or "Билли - женщина" or even "Билли - это она" (Billy is a "she").