Affixation: prefixes change meaning, suffixes change word class

A long word is usually a short word with parts added. Read it from the root outwards: in decentralization, central becomes a verb (centralize), is reversed (decentralize) and is then turned into a noun.

• The scheme was badly mismanaged from the start.
• Small firms often outperform their larger rivals.
• Cutting the training budget proved counterproductive.

Conversion: a new word class, the same form

English freely uses a word in a new class without adding anything. You recognise the class from the position and the endings: after to or a subject it is a verb, after a / the it is a noun.