Heng-bok = happiness
Heng-bok-ka-da(basic form of the verb) = be happy
Sa-rang(noun) = love
Ee = It's one of Korean postpositions.
For example 'Heng-bok-kan-de Seul-puh' = (I'm) happy but I'm sad
'Heng-bok-ka-da Geun-deh Seul-puh'
We mostly say Geun-de as the meaning of 'but' or 'by the way' in spoken Korean.
I love you
Sarangheh, it's said between couples and very close friends. Well… I say it to my parents(I usually don't use the honorific when I talk with them. Ah, except for when I'm scolded :P )
Uh-dduk-ke(=how) Sa-rang-ee Byu-Ne-yo. How does love change.