One way to find synonyms is by looking them up in a thesaurus. Similar to a dictionary, this is a reference book that lists words grouped by similar meaning, so you may find "principle" grouped with "code," "standard," "belief," "opinion," and also with "rule," "law," "theory" and "notion." If you have a computer and the Microsoft Word editor, select the word you want to change with a synonym, right-click on it and select either "Synonyms" or "Thesaurus" in the menu.
Nouns are parts of speech denoting a person or a thing, and are usually replaced by pronouns in a longer paragraph to avoid repetition. It is important to learn how to use different words with the same meaning to convey a powerful message, especially in writing. Synonyms like "affront" and "indignity" can replace the more common word "insult"; "peril" and "jeopardy" can be used instead of "danger," and "defect"; "imperfection" and "blemish" have similar meanings to "flaw."
Verbs should be replaced by synonyms, especially when they are included in reporting dialogues or in a sequence of actions. Thus, instead of repeating "he said" you can use the words "state," "affirm," "announce" or "utter." "Run" can be replaced by "scamper," "lope," "jog," "sprint" or "trot," the choice depending on the image that you want to create. Similarly, "polish" can be expressed by "rub," "furbish," "burnish" or "scour."
Not all words from a word group are perfect synonyms, so when you replace a word, make sure the synonym you use fits the context. For example, you can say "It's a glorious/magnificent/splendid day," but not "It's a famous day," even if "famous" is a synonym of "glorious," but in a different context. Instead of "calm" you may use "tranquil" or "serene"; "busy" can be replaced by "industrious" or "assiduous"; "enough" can be expressed by "adequate" or "sufficient."
Adverbs are parts of speech that characterize the action of verbs. As most adverbs come from adjectives, they generally have the same synonyms as them, but in an adverb form and meaning. "He was walking quickly" can be expressed as "He was walking fast/hurriedly/hastily/swiftly." Other synonyms worth remembering are: for "readily" --- "willingly," "voluntarily," "eagerly," "keenly" or "freely"; "remarkably" can be replaced by "astonishingly," "amazingly" or "outstandingly."