In short

To say “more than”, glue 보다 (boda) to the noun you are measuring against and put 더 (deo, more) before the adjective: 커피보다 더 좋아요 (keopiboda deo joayo, better than coffee). For “the most”, drop 제일 (jeil) or 가장 (gajang) in front of the adjective. Because 보다 marks the standard, the two nouns can come in either order. “Like/as” is the separate particle 처럼/같이, and “the same as / different from” needs 와/과 plus a verb.

The rule

Step 1 - N보다 (+ 더): comparison

Attach 보다 directly to the noun that is the standard of comparison (the English “than X” noun), then usually add 더 before the quality word:

Comparee + (은/는·이/가) + Standard + 보다 + 더 + Adjective

차가 커피보다 더 비싸요 (chaga keopiboda deo bissayo, tea is more expensive than coffee). 보다 is a particle, so it takes no space and needs no allomorph - it looks the same after a vowel or a 받침 (커피보다, 물보다). Since 보다 itself labels the standard, Korean word order is free: 커피보다 차를 더 좋아해요 and 차를 커피보다 더 좋아해요 mean the same I like tea more than coffee. 더 is optional but very common; its opposite is 덜 (deol, less): 여름보다 덜 더워요 (yeoreumboda deol deowoyo, less hot than summer). Sharpen the degree with 훨씬 (hwolssin, far, much) or soften it with 조금 / 좀 (jogeum / jom, a little): 훨씬 더 커요 (hwolssin deo keoyo, much bigger).

Step 2 - 제일 / 가장: the superlative

Put 제일 or 가장 before the adjective or adverb - Korean has no “-est” suffix. 제일 싸요 (jeil ssayo, is the cheapest), 가장 빨라요 (gajang ppallayo, is the fastest). To say “the most … N”, use the modifier form (lesson 36) between 제일/가장 and the noun: 제일 맛있는 음식 (jeil masinneun eumsik, the most delicious food), 가장 높은 산 (gajang nopeun san, the highest mountain). Name the field of comparison with N 중에서 (jungeseo, among N) or N에서 (in N): 과일 중에서 딸기를 제일 좋아해요 (gwail jungeseo ttalgireul jeil joahaeyo, among fruits I like strawberries most).

Step 3 - Similarity and equality

Two separate tools. 처럼 and 같이 are particles meaning like / as, glued to the noun with no space: 천사처럼 (cheonsacheoreom, like an angel), 얼음같이 (eoreumgachi, like ice). 같다 / 다르다 / 비슷하다 are verbs (be the same / different / similar) and take the noun with 와/과 (lesson 18): 저와 같아요 (jeowa gatayo, is the same as me), 저와 달라요 (jeowa dallayo, is different from me - 다르다 is 르-irregular, lesson 39). 만큼 (mankeum) means as much as: 형만큼 키가 커요 (hyeongmankeum kiga keoyo, as tall as my older brother).

Step 4 - The double-subject comparison

Korean often frames “A is taller than B” as A - as for height - is big. The comparee takes 이/가 (or 은/는), the measured attribute takes its own 이/가, and the standard sits between them with 보다: 동생이 저보다 키가 커요 (dongsaengi jeoboda kiga keoyo, my younger sibling is taller than me, literally sibling - than me - height - is big).

Step 5 - Negatives and questions

“Not particularly” pairs 별로 (byeollo) with a negative: 별로 안 비싸요 (byeollo an bissayo, not particularly expensive). “Not that …” is 그렇게 …-지 않아요 (geureoke …-ji anayo): 그렇게 크지 않아요 (geureoke keuji anayo, not that big). To ask, use 어느 게 (eoneu ge, which one) or 뭐가 / 누가 (mwoga / nuga, what / who): 어느 게 더 좋아요? (eoneu ge deo joayo?), 뭐가 제일 싸요? (mwoga jeil ssayo?).

Forms & patterns

Comparison and similarity particles - one form, glued to any noun (no space, no allomorph):

와/과 with 같다·다르다·비슷하다 - this one DOES split by 받침:

Superlative and degree words:

Examples

Common mistakes

• 이것와 같아요 (igeotwa gatayo) -> 이것과 같아요 (igeotgwa gatayo) - a 받침 noun (이것) selects 과, never *와; only vowel-final nouns take 와.
• 생각이 저와 달아요 (saenggagi jeowa darayo) -> 생각이 저와 달라요 (saenggagi jeowa dallayo) - 다르다 is 르-irregular: the stem doubles the ㄹ, giving 달라요, not *달아요.
• 저는 사과를 좋아요 (jeoneun sagwareul joayo) -> 저는 사과를 좋아해요 (jeoneun sagwareul joahaeyo) - 좋다 (be good/likeable) can’t take an object; the verb to like is 좋아하다, or say 사과가 좋아요 with 이/가.
• 이 영화는 별로 무서워요 (i yeonghwaneun byeollo museowoyo) -> 이 영화는 별로 안 무서워요 (i yeonghwaneun byeollo an museowoyo) - 별로 must be answered by a negative (안 / -지 않다); on its own it is ungrammatical.
• 제일 맛있다 음식 (jeil masitda eumsik) -> 제일 맛있는 음식 (jeil masinneun eumsik) - “the most … N” needs the modifier form (-는/-(으)ㄴ) on the adjective, not its dictionary form.

Tips

• 제일 vs 가장. Both mean most and are interchangeable; 제일 (from Sino-Korean 第一, number one) is the everyday spoken choice, 가장 leans a touch more formal/written.
• Particle vs verb. 처럼·같이·만큼 are particles - they glue onto the noun with no space and never conjugate. 같다·다르다·비슷하다 are verbs - they need 와/과 and take endings (같아요, 달라요, 비슷해요). Don’t confuse 같이 (like, particle) with 같다 (be the same, verb) - or with the adverb 같이 (together) you already know from 같이 가요: the particle is written attached to its noun (얼음같이, 어른같이), while the adverb stands as its own word (친구하고 같이 갔어요).
• Korean front-loads the standard. English puts it last (“taller than me”); Korean puts it first with 보다 (저보다 커요). Learn the frame Standard + 보다 + 더 + adjective and the order of the two nouns stops mattering.
• 더 is optional, 덜 is less common. 커피보다 좋아요 already implies “better than coffee”. Rather than 덜 (less), Koreans often just switch to the opposite adjective - 덜 비싸요 becomes 더 싸요 (cheaper).