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

Compounds Expand your vocabulary by studying more complex words built by the 'core words'.
Etymology Explore the origin of the 'core words'.
Wordsense Learn about the wordsenses of the english term.

TOPIK 11000 KOREAN WORDS

☆ GRASP; UNDERSTAND; TAKE IN phát hiện ra, nhận ra
HSK 3.0 11000 CHINESE WORDS
5 发觉  fājué light upon, discovery, find, see, espy, discover, perceive, strike, come upon, detection, come across, happen upon, detect, chance upon, chance on

ENGLISH 6000 THEME WORDS

OXFORD 5000 CORE WORDS

TANAKA 6000 CORE WORDS