안녕하세요 Readers! I've been studying Korean for almost 6 years now and I recently started studying Japanese last year - about 9 months ago. This post will just be me comparing the 2 languages and pointing out their similarities.
The actual answer of which is harder or which is easier is for you to come up with and I also think it depends on your background - for example your native language or other languages you know well, which one you learn first, how much you have learned, etc.
For Example: I know some people that have learned Japanese that find Korean hard and I know Korean learners who find Japanese hard or vice versa they find it easier.
SIMILARITY #1 - Sentence Structure
Japanese & Korean have the exact same sentence structure. Instead of me having to take time to learn it I was able to skip over that, because I'm already used to it in Korean. Click highlighted words for audio!
The General Structure (which is sometimes more flexible than this) :
Who | When | Where | What | How | Verb
Example:
I want to watch a movie at Jisoo’s house tonight.
저는 - 私は
오늘밤 - 今晩
지수의 집에 - ジスの家に
영화를 - 映画を
보(다) - 見(る)
고 싶다 - たい
(어)요 - です
SIMILARITY #2 - Numbers
You make numbers in Japanese the same way as in Korean. As long as you know the first 10 numbers, the rest become easy. Also some of the numbers even sound alike, making them easier to memorize. A major difference is that Korean has 2 number systems - one that’s Korean based and another that comes from Chinese. We’ll look at the Chinese one here - sino numbers.
Korean number audio - here!
Japanese number audio - here!
(il) 일 - いち (ichi) = 1
(ee) 이 - に (ni) = 2
(sam) 삼 - さん (san) = 3
(sa) 사 - よん (yon) = 4
(o) 오 - ご (go) = 5
(yuk) 육 - ろく (roku) = 6
(chil) 칠 - なな / しち (nana/shichi) = 7
(pal) 팔 - はち (hachi) = 8
(gu) 구 - く / きゅう (ku/ kyuu) = 9
(ship) 십 - じゅう (jyuu) = 10
(shipil) 십일 - じゅういち (jyuuichi) = 11 (10 + 1)
(shipo)십오 - じゅうご (jyuugo) = 15
(eeship) 이십 - にじゅう (nijyuu) = 20 (2 x 10)
(samship) 삼십 - さんじゅう (sanjyuu) = 30
(gushipo) 구십오 - きゅうじゅうご (kyuujyuugo) = 95 (90 + 5)
(baek) 백 - ひゃく(hyaku) = 100
…and so on and so forth
This also goes for ages and telling the time. Both languages follow the same structure for this too.
AGE - Basically just attaching (sal) 살 / さい (sai) = Age to the number
19 years old
(yeolahop sal) 19살 (Korean uses different number system here but it’s still 10 + 9)
(jūkyūsai) 19歳
TIME - it’s more complicated in Korean because we have 2 number systems.
Native Korean Number + O'clock/Hour + Sino Number + Minute
9:10 o'clock
SIMILARITY #3 - Particles
It seems like the same particles in Japanese are essentially the same as Korean. They have topic marker, object marker, time/location-marking particle, etc. There might be some unique ones for each language - like I said I’m a beginner in Japanese and probably haven’t come across it yet. Here's a decently sized list to of them that I noticed off the bat.
(eun/neun) 은/는 > は (wa) - topic marker
(ee/ga) 이/가 > が (ka) - subject marker
(eul/reul) 을/를 > を (wo) - object marker
(eh) 에 > に (ni) - time/location marking particle
(eseo) 에서 > で (de) - doing action at location
(ui) 의 > の (no) - possession particle (..'s)
(uro) (으)로 > で (de) - a means of doing something
(uro) (으)로 > へ (e) - to, towards
(buteo/kaji)에서/부터-까지 > から/まで (kara/made) - from/since-until
(mada) 마다 > まい (mai) - every, each
(to) 도 > も(mo) - also, too
(gwa/wa) 과/와/이랑/하고 (there are many ways to say and in Korean) > と (to) - and
(ina) (이)나 > や (ya) - and; or
(ji/jiyo/jyo) 지/지요 (죠) > ね (ne) - right?
(ege/hante) 에게 (한테) - に (ni) - to, from
(man) 만 > だけ (dake) - only
I noticed that most of the time these particles function the exact same, however there are some instances in which they cannot be used the same way in both languages. For example, sometimes は(topic particle) is used instead of が (subject particle) when in Korean you’d use 이/가 (subject particle) instead.
Example:
where is the bathroom?
*if we followed my list above word for word and used the Japanese example and translated to Korean it would become: 화장실은 어디예요? which doesn’t sound as natural and may be seen as “wrong”. トイレがどこですか would probably have the same affect as the Korean sentence for reference.
So of course you must learn the rules in each language of when a certain particle must be used and not just look at this list and apply it to both languages as if it’s a “one size fits all” kind of thing.
SIMILARITY #4 - Vocabulary
I won’t go into much detail, because there are hundreds of words between these languages that are pronounced similarly or the same and share the same meanings. I made a full other post with more - here!
EXAMPLES:
(gajoku) 가족 = 家族 - かぞ (kazoku) = family
(junbi) 준비 = 準備 - じゆんび (jun'bi) = prepare
(sajin) 사진 = 写真 - しゃしん (shashin) = picture
(dosogwan) 도서관 = 図書館 - としよがん (toshokan) = library
(byongwon) 병원 = 病院 - びょういん (byōin’) = hospital
WHICH IS HARDER / EASIER: just my opinion by the way yours may be different and that’s okay! I would say it depends. When it comes to vocabulary words - Japanese could be called "harder" because of Kanji, although in the way of grammar Korean and Japanese are very alike. Pronunciation is a bit trickier in Korean as well as reading, although reading is slightly harder in Japanese. Personally though I find Japanese easier to understand when listening as opposed to Korean.