1. Adverb '안'
2. Adverb '못'
3. The marker '-에서'
4. The objective marker '-을/를'
5. The pre-ending '-았/었/였-'
1. Adverb '안' : do not
   
  The abverb '안' is used to express the negative and means 'do not'. '안' is put before the verb.
   
 
 
학교에
안 갔어요.
 
점심을
안 먹었어요.
   
 
   
2. Adverb '못' : want to do but can not
   
  The adverb '못' is used with action verbs, and means impossibility or strong denial and refusal.
   
 
 
파티에 못 갔어요.
 
형을 못 만났어요.
   
 
   
3. The marker '-에서' : at/in,from
   
  The marker '-에서' has two meanings. One is 'at' or 'in' indicating the place where an action takes place. Another meaning is 'from', indicating a starting point or cause.
   
 
 
맥도널드에서 점심을 먹었어요.
 
스페인에서 왔어요.
   
4. The objective marker '-을/를'
   
  The marker '-을/를' is attached to a Noun to indicate the direct object of a transitive verb. '-를' is used after a vowel while '을' is used after a consonant.
   
 
 
생일파티를 했어요.
 
점심을 먹었어요.
   
 

   
5. The pre-ending '-았/었/였-'
   
  This is used to indicate an action which took place in the past or a condition which used to exist.
   
  (1) -았-
When the final vowel of the verb stem is 'ㅏ,ㅗ', it takes '-았-'
   
 
  많다: 많 +   -> 많았어요.  
  좋다: 좋 + 았어요. -> 좋았어요.  
  만나다: 만나 +   -> 만나았어요. -> 만났어요. (contraction)
  오다: 오 +   -> 오았어요. -> 왔어요. (contracion)
   
  (2) -었-
When the final vowel of the verb stem is any other vowel like 'ㅓ, ㅜ, ㅡ, ㅣ', it takes '-었-'.
   
 
  먹다: 먹 +   -> 먹었어요.  
  읽다: 읽 + 었어요. -> 읽었어요.  
  가르치다: 가르치 +   -> 가르치었어요. -> 가르쳤어요. (contraction)
  찍다: 찍 +   -> 찍었어요.  
   
 

(3) -였-
When the verb is a '하다' verb, it takes '-였-'.
   
 
  산책하다: 산책하 +   -> 산책하였어요. -> 산책했어요. (contraction)
  기뻐하다: 기뻐하 + 였어요. -> 기뻐하였어요. -> 기뻐했어요. (contraction)
  가르치다: 가르치 +   -> 공부하였어요. -> 가르쳤어요. (contraction)