Verb -았어야/-었어야 했는데
Indicates regret about something that you think it should have been done or should not have been done in the past.
Can also be used to connect clauses.
It can also be used in the form of -았어야/-었어야 됐는데 without changing its meaning.
Verb -자고 하다
Used to pass on to another person a suggestion that was made to so something together.
Use -지 말지고 하다 for negative suggestions
아무리 Adjective/Verb -아도/-어도
아무리 is used to indicate the degree or severity. It is used in conjunction with -아도/-어도 to indicate that the following situation or action occurs even though the previous situation or degree of behavior is severe.
Adjective/Verb -잖아요
Used to identify what the listener or other people already know, or to remind the other person of something they can’t recall well. It is a spoken language and generally used between people who have a close relationship or directed towards a person of lower social status.
When talking about past events, use -았잖아요/-었잖아요.
When combined with a noun, use -(이)잖아요 for the present tense, and -이었잖아요/-이였잖아요 for the past tense.
저 두 사람은 정말 친한 것 같아요. 매일 같이 다녀요. 두 사람이 어렸을 때부터 친한 친구잖아요.
미아 씨가 독일 말을 참 잘하네요. 어머니가 독일 사람이잖아요.
선생님도 팅팅 씨를 아세요? 팅팅 씨도 전에 언어교육원 학생이었잖아요.
새 커피숍이 생겼네요. 옛날에는 여기가 꽃가게였잖아요. 네, 한 달 전에 생겼어요.