Many words in the English Language belong to a “family” of words. Each word in a word family is derived from the same root. By understanding how English words are formed, you can guess the meaning of a word if you know the meaning of its root.
Here are some examples.
Plaint – an accusation or charge; a complaint or lamentation.
Plantiff – a person who accuses another in a court of law.
Plaintive – sounding sad or mournful.
Liquid – a substance that flows freely but that is of constant volume.
Liquidate – to convert assets into cash.
Liquidator – a person who liquidates a business or company.
Liquidation – the act or process of liquidating a company.