The ㅅ consonant
I'm only a few lessons in and am an actual beginner. Is there any chance someone can add to the tips & notes section a one-liner regarding ㅅ ? I was going nuts for a few lessons wondering why something like 갓 is not pronounced similarly to "gas" in English (thought it was a bug and google translate says it like "gan").
In addition to that, does ㅅ always turn into the T sound when its at the end of a word? Are there any other cases where it doesn't have the S sound?
Korean doesn't end anything with a strong consonant sound, so for those short words like 것, 밥, 읽, they sound like you're barely finishing the words - ga(t), ba(p), ee(k). It's not hard to mimic after a little practice.
As for your second question, yes ㅅ always is a light T sound at the end of a word. The same goes for ㅈ, ㅉ, ㅊ, ㄷ, ㄸ, ㅌ. Other cases: 있다 - eet-da, 갖다 - gat-da, 듣다 - deut-da, 믿다 - meet-da, etc etc
The exception: 맛없다 - but the ㅅ is followed by the vowel 어! Yes it is, but they decided long long long ago that they pronounce this NOT like Ma-seop-da, but like Mat-oep-da. In fact since it's a light sound when on the bottom, when you pronounce it in a word like this, it will sound more like a D. Ma-(d)eop-da
Wow I did not know about 맛없다 being pronounced with the ㅅ as ㄷ. This is such a strange 받침 ('batchim' is the final consonant(s) of a Hangul syllable) rule that I have never noticed before so I had to dig a little deeper. I unearthed a couple of reddit threads that were helpful since this comment had me scratching my head! If someone is interested they are 맛있어요 pronunciation and "Official" rules of Korean pronunciation, summarized in English.
Disclaimer: I am not a native Korean speaker and the following is simply an observation as a beginner, so please let me know if you notice any mistakes!
Basically from what I can tell, 맛없다 is pronounced as "마덦다" (ma-deob-da) because 없다 is a what is called a lexical morpheme or function morpheme. Lexical morphemes are words that have meaning on their own, i.e. 없다 (to not have/not exist at) and 맛 (taste) both have meanings by themselves and therefore are lexical morphemes. Grammatical morphemes are sounds intermingled with speech that, well, serve a purpose grammatically. In Korean, particles are grammatical morphemes. For example the conjugated verb ending -어요 does not mean anything on its own, similar to suffix '-ed' or the word 'at' in English.
The pronunciation of the 받침in this case (맛없다) is from the rules: (as quoted from kjoonlee in the second link above)
(15. If a 받침 meets a lexical morpheme that starts with /ㅏㅓㅗㅜㅟ/, reduce the 받침 before moving the 받침 to the next syllable.
(15.1. Rule 15 explains [마덥따]. Rule 15.1 says that [마싣따] and [마딛따] are both good pronunciations for 맛있다.
Rule 15 is stating that in the event that if a 받침 is followed by [ㅏㅓㅗㅜㅟ], it is reduced its corresponding uttered form first before appending the next word. So, I believe that 맛없어요 is pronounced as 마덥서요. 맛 by itself is pronounced as "맏" (mat), and is then followed by another lexical morpheme 없다. The ㅅ from 없 goes to the placeholder ㅇ in -어요, which as far as I know is simply a general rule of Hangul (which you've probably heard of if you've read this far). It's in the case of being followed by a lexical morpheme where rule 15 applies, unless if the vowel is ㅣ. Then it could be pronounced either way (Rule 15.1).