These words all refer to the process of making something over or making it different. Change , the most general and least formal, can mean any process of differentiation, slight or great, in appearance or essence, in quality or quantity: changing the desert into farmland; changing his mind; changing the way she wore her hair.

Alter , convert and modify suggest relatively slight revisions of something, generally in appearance or use. Each also has a use with somewhat different effect for a change in attitude or belief. As listed, these words move from the slightly to the highly formal, with perhaps a similar progression in implication, from lesser to greater change. Alter , most commonly, refers to changing the fit of clothes, either making them looser or tighter by letting out or taking in seams: the dressmaker who altered the hemline of the skirt. It also commonly refers to the redecoration of buildings: workmen altering the bookshop into a self-service grocery. In both these uses, alter implies that the basic structure is worked with and around rather than changed in itself, although no value judgement is present concerning the result. Alter , more than any of these words except change , has a wide range of application.

• He altered his stand on birth control; She altered the mistake on the price tag.

Covert suggests the adaptation of an object by a specially designed addition that will increase its usefulness: an attachment that converts your vacuum cleaner into a paint sprayer. When used of attitudes or beliefs, convert suggests a far more drastic change than alter: the man who was converted to Buddhism. Modify , when used of objects, suggests more basic changes than alter or convert , in which function more importantly than appearance is changed : car aerials modified by teenagers into lethal weapons. When applied to attitudes, however, modify implies less change than either alter or convert . It often has a special overtone of making less extreme.

• He didn’t alter his position so much as modify its severity; in any case, you could hardly say he was converted by the arguments of the opposition.

The remaining words suggest more drastic changes than the preceding, changes so profound that an entirely new entity may appear to have taken the place of the old. Transmute emphasizes an elemental change in the inner structure of a material, often implying a move from a lower to a higher state: coal transmuted to diamonds by aeons of intense pressure; alchemists vainly trying to transmute lead into gold. Change of this magnitude, obviously, is not accomplished by revision, as in alter , or by addition, as in convert . Transform suggests change equally as profound, but, in concentrating on outward form or appearance, it is perhaps slightly less intense than transmute and certainly more general. Transform may suggest change in a person or a definite entity, transmute in a less well-defined quantity; transmute also tends to suggest a slow, analysable or scientific process, transform a sudden or mystical change: the frog that was transformed into a prince; plans that were transformed overnight into reality. Transform also lends itself to hyperbole, perhaps overused: lighted candles that transformed the oak table into elegant dining table.

Transfigure intensifies the mystical element in transform , adding a note of supernatural or religious rapture: the statue of St. Teresa transfigure by ecstasy. When used hyperbolically of more common circumstances, a positive or joyful change is indicated: her plain features transfigured with tenderness. Transmogrify , on the other hand, always stresses negative change, bizarre or ugly: the peasant lad transmogrified into a dragon. In more usual circumstances, the effect is comic: the graceful child transmogrified into a gangling adolescent.