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Core Words Familarize yourself with the 'core words'.
Compounds Expand your vocabulary by studying more complex words built by the 'core words'.
Etymology Explore the origin of the 'core words'.

{n}	trouble	(difficulty)	Schwierigkeit {f}
{n}	trouble	(distressful or dangerous situation)	Ärger {m}
{n}	trouble	(effort)	Anstrengung {f}, Bemühung {f}, Mühe {f}
{n}	trouble	(malfunction)	Störung {f}
{n}	trouble	Mühe	{f}, Sorge {f}, Ärger {m}, Ungemach {n}
{v}	trouble	(to bother; to annoy)	beunruhigen, belästigen, bekümmern