power: In the sense of “a great number or quantity,” this word is an undesirable colloquialism that has gained ground especially in rural districts. One may say of a man “He was a power among the people,” but not “A power of people heard him.”
practical: Do not confound with practicable. The former means “that can be put into practise or rendered applicable for use; as, practical knowledge”; whereas the latter is perhaps best expressed by the synonym “feasible.” Practical has a general application, being governed by actual use and experience; as, practical statesmanship or wisdom: practicable, on the contrary, is particular, and signifies the suitability of the particular thing named to the desired end. Thus one may know a practical man but not a practicable one.
pray, prey: Exercise care in using these homophones. Etymologically they are distinct. Pray is from Old French praier, to ask; while prey is from Old French preier, booty, probably from the Latin prœhendo, to seize. Note the difference in spelling.
precedent, president: Although almost homophones these terms have widely different meanings. A precedent is something that has occurred before in time and is considered as an established rule or an authorized example; a president is the head of a nation, society, or the like.
predicate, predict: Though these words are both derived from the same Latin source, the one must not be used for the other. To predict is to foretell, whereas to predicate is to proclaim as inherent. In United States usage predicate, with on or upon, is sometimes treated as synonymous with establish; as, “On what do you predicate the assertion?”
prefer: The act or thing preferred should never be followed by than. Prefer is properly followed by the preposition to, or occasionally by above or before. Thus do not say “I prefer to talk than to dance,” but “I prefer talking to dancing.”
preferable: If the preference is stated in terms, as “This is preferable to that,” the word is followed by the preposition to—never by than. The preference may, however, be implied; as, “This is preferable.”
prejudice: Sometimes erroneously used for “prepossess” or “predispose.” A prepossession is always favorable, a prejudice always unfavorable, unless the contrary is expressly stated. Predispose means “to dispose or incline beforehand.” Therefore, we should not say that a person is prejudiced in any one’s favor but that he is prepossessed or predisposed.
preposition: “The part of speech or particle that denotes the relation of an object to an action or thing; so called because it is usually placed before its object.” The correct use of these little words is often puzzling to persons of education. For the purpose of their guidance the following partial list is given. A comprehensive work on the subject of their correct use is “English Synonyms, Antonyms and Prepositions,” by Dr. James C. Fernald.