What this suffix does
The suffix -ment takes a verb and creates the noun that names the action, process or its concrete result. From "develop" you get "development"; from "agree" you get "agreement"; from "pay" you get "payment".
It is the second most common noun-forming suffix after -tion. The key difference: -tion tends to pair with Latin-origin verbs, while -ment pairs more often with native English and French-origin verbs.
Common Spanish cognates
Many -ment words have near-identical Spanish equivalents:
movement = movimiento
government = gobierno
argument = argumento
document = documento
treatment = tratamiento
If you know a Spanish -miento or -ción word, try converting it to -ment in English. The bridge works in both directions and is especially useful for academic and business reading.
-ment names both processes and results
Unlike -tion (which usually names an abstract action), -ment often names both the process and the concrete result or document.
agreement = the process of agreeing AND the signed document.
payment = the act of paying AND the money handed over.
statement = the act of stating AND the written record.
Always check context to see whether a -ment word refers to the process or the outcome.