1 (wiktionary) 2 (vi.wikipedia) 3 (en.wikipedia) 4 (glosbe)

Core Words Familarize yourself with the 'core words'.
Compounds Expand your vocabulary by studying more complex words built by the 'core words'.
Wordsense Learn about the wordsenses of the english term.

ETYMOLOGY

HAN VIET: lưỡng đang 两次

KOREAN 3.0	Eng	Wordtype	Etym.	Gb	Vie
☆☆☆	SECOND	Noun		两次	lần thứ hai, lần hai