Basic Grammar - 기본 문법
Simple Past Tense 과거 시제
I watched an interesting movie last night.
She worked at a restaurant last summer.
Yesterday, I played computer games.
Past Progressive 과거진행형
(was/were + gerund - 동명사)
I was reading  a book when the phone rang.
We were watching TV and they were studying during the storm.
Present Perfect 현재완료
(have/has + 과거분사)
I have been to Seoul several times.
He has written many books.
A few selected verbs with past tense forms and past participles.
Original form Past tense Past Participle
(원형) 과거 과거분사
hit hit hit
read read read
set set set
buy bought bought
sell sold sold
feed fed fed
teach taught taught
hear heard heard
sleep slept slept
win won won
begin began begun
write wrote written
swim swam swum
sing sang sung
Wishes about the future … 미래의 소원
I wish I could live in Jejudo. 
제주도에서 살수 있었으면 좋겠다.
Present - (현재 사실의 반대)
I wish I could do that.
그것을 할수 있었으면 좋을텐데 …
Past - (과거 사실의 반대)
I wish I could have done that.
그것을 할수 있었으면 좋았을 텐데.
Using Modals (auxiliary verbs), For + Noun (명사) and infinitives. (부정사)
auxiliary verbs (조동사) adjective (형용사)  
cannot (can't) impossible 불가능한
can/may possible 가능한
should important 중요한
must necessary 필요한
I can't fly. It is impossible for me to fly.  
You may borrow my pen. It is possible for you to borrow my pen.
We should learn English. It is important for us to learn English.
You must bring your book to class.  
It is necessary for you to bring your book to class.  
Using Modals (auxiliary verbs - 조동사)
modals usage 용법
can / could 능력; 가능; 금지 (~할 수 있다) ability, possiblity, prohibition
may / might 허가; 추측; 가능 (~ 해도 좋다) permission, probability, possiblity
will / would 거부; 습관; 추측 refusal, habits, probability
must 필요; 의무; (해야 한다) necessity, obligation
should 필요; 의무; (해야 한다) necessity, obligation
Noun clauses (명사절)