달다 and 달콤하다 both mean sweet (adj.).
But while 달다 simply describes the "sugary" taste, 달콤하다 is a more illustrative word. With the addition of "콤" (= fat taste of nuts, buttery nutlike flavor), 달콤하다 reflects the more savoury/smooth aspect of the sweetness. It is recognized that 'fat' does improve the taste in food.
- 콤하다 is usually seen added to some primary flavors for that reason 새-콤하다 (pleasantly sour, tangy, sharpish) or 매-콤하다 (pleasantly spicy, zesty )
In short, 달다 = sweet; 달콤하다 = pleasantly sweet
단 와인 = sweet wine
달콤한 와인 = smooth wine
(actual meaning) initial, original, prototypical;
(usage) first, top, primary
번 = time; 째 = round, turn
—번째 denotes position in the list of things. Used as counter for ordinal numbers. Hence translated into English as st, nd, rd & th.
첫번째 = Lit. initial time round = first (1st).
In common usage, it is often abbreviated to '첫' (hence the confusion).
Number [번]째 + NOUN.
• Number: Use pure Korean set of numbers (up to 20), apart from: 1st = 첫째 or 1st time = 첫 번째.
• space needed between Number and 번째.
• 첫 comes from 처음, the beginning.
• use proper ordinals 첫째; 둘째 etc. for counting and ordering and use 첫 번째; 두 번째 etc for repetitive events/actions and ranking/grading.
• after 20, either pure Korean or sino Korean numbers may apply but pure Koreans are preferred.
첫 번째 와인(은) = First/top grade wine (topic subject)