How are words in English built or formed?

Words in English are formed through various processes, including derivation, compounding, and inflection. Derivation involves adding prefixes or suffixes to a root Word to create new meanings (e.g., "happy" becomes "unhappy"). Compounding combines two or more Words to form a new Word (e.g., "toothbrush"). Inflection modifies a Word to express different grammatical categories, such as tense or number (e.g., "walk" becomes "walked").