I am a bit frustrated with Duo in Hebrew. I just had to translate an animal that I was never really presented. I had seen it besides other animals, but never had to choose it, and then without the chance to check with hovering, I had to type סוס in Hebrew. It worked, but it reassured me that I am right with my impression that sometimes I am never even presented with words that I should learn in a lesson. Sometimes they appear for the first time when I strenghten the lesson. It seems like the algorythm for Hebrew is not quite mature yet. By the way: I would have loved to report this right in the exercise concerned, but I didn't have the option. So I ticked the only thing there was to tick: "The picture doesn't match the something I can't remember". It would be nice to have the chance to give feedback for every example, not just some.
:D thanks! I am a bit of a language magpie - ooh, shiny 8-o I only claim any kind of competence in Russian, French, Hebrew and Esperanto (well besides English), and goodness knows I still make fistfuls of errors in those depending on the day.
But... I'm incapable of not trying a language (especially when it's offered for free :3), and that goes double for Slavic languages, so I'm a serial dabbler. Hebrew has taken most of my energy for a while now, but I dip in and out of others.
"I "only" claim language competence in 5 languages. " Is still an impressive thing to state, so good on you.
I am actually going to try to dabble in some languages, just for fun and for having a broad general knowledge.
I had Latin in school (of which I remember a small bit), speak German natively and am fluent in English so when reading I can get the gist of Esperanto, currently learning Hebrew.
I did also dabble a small bit in conlanging for some roleplay stuff, but studying math just eats up your time ^^'
Let me try to dissolve the מסתורין (ha ha).
First, ס vs ש (the latter with it's /s/ sound): the uses of ש are rare survivors of biblical Hebrew. Already in Mishnaic Hebrew they started to replace it (ancient Hebrew words!) with ס. Modern Hebrew by and large followed the trend and preferred ס for most of these words. ש is just not used for /s/ sound in loan words, period.
Now, ת vs ט: for the last century or so, for loan words, it's been consistently ט for "t" (or the Greek τ), and ת for "th" (or the Greek θ). Doesn't matter if at the beginning or the middle of the word. (Ironically, you'll notice that by the letter names ט = θ and ת = τ.) I think that the reason is that in many Ashkenazy dialects, when reading Hebrew words, ת was pronounced as /th/ or /s/. I sometimes encounter very rare exceptions (stethoscope is mostly written סטטוסקופ), which I consider a confusion (I see that some pedantic souls do write סטתוסקופ, and I'll happily join them should I ever need to write this word...).
So, what's the deal with מסתורין? It was simply loaned in Rabbinic times (from Greek), and they seemed to care less about consistency then. I was surprised to find now that the Rabbinic literature also used מסטורין. The ת version prevailed here, maybe because of the semantic similarity - accidental, I believe - to the old semitic / biblical root סתר ("hide" etc.)
That's what I've read, too, also noting that loanwords with TH (thus with the letter T but not the T sound in English) are likely to use ת. An example with initial TH: theater תֵּאַטְרוֹן; an example with medial TH and medial T: מָתֶמָטִיקָה.
Example with initial S, symphony סִימְפוֹנְיָה; example with medial S and medial T (but using ת), mystery מִסְתּוֹרִין.
(Examples from Morfix.)