Core Pattern Rule: -(으)ㄴ/는 데다가
This pattern means "on top of that" or "in addition to." It's used to add a second, related piece of information to an existing fact or situation, often to emphasize the combined effect.
Formation
Adjectives: Attach -ㄴ 데다가 to stems ending in a vowel (e.g., 크다 → 큰 데다가) and -은 데다가 to stems ending in a consonant (e.g., 작다 → 작은 데다가).
Verbs: Always attach -는 데다가 to the verb stem, regardless of whether it ends in a vowel or consonant (e.g., 오다 → 오는 데다가, 먹다 → 먹는 데다가).
Past Tense Verbs: Attach -았/었- to the verb stem, followed by -는 데다가 (e.g., 걸렸다 → 걸렸는 데다가). This is often shortened to -ㄴ/은 데다가 in speech (e.g., 감기 걸린 데다가).
있다/없다: These act like verbs, taking -는 데다가 (e.g., 없는 데다가).
Usage
The two clauses connected by this pattern should be related. Typically, they are both positive or both negative, compounding the overall situation.
비 오는 데다가 차도 막혀. / 똑똑한 데다가 친절해. / 돈도 없는 데다가 시간도 없어. / 늦은 데다가 지갑도 안 가져왔어.
Nuance: Compounding the Situation
This pattern does more than just list two facts; it emphasizes how the second fact makes the first one even more intense, whether for better or worse.
Negative + Negative
This is very common for complaining or explaining a difficult situation. The second clause makes things sound worse.
Example: 비싼 데다가 맛도 없어. (It's expensive, and to make matters worse, it doesn't even taste good.)
Positive + Positive
Use this to praise someone or describe a great situation. The second clause adds another layer of positivity.
Example: 날씨도 좋은 데다가 경치도 좋아. (The weather is nice, and on top of that, the scenery is great too.)
The Role of '도'
Notice how the particle 도 (also, too, even) is almost always used in the second clause. It's the key ingredient that reinforces the "on top of that" feeling.
비싼 데다가 맛도 없어. / 똑똑한 데다가 친절해. / 돈도 없는 데다가 빚도 있어. / 날씨도 좋은 데다가 경치도 좋아.