These words describe things that are made, done, understood, etc., without undue difficulty, but they are not close synonyms. Simple and easy are the most general terms. In this context simple refers to something that is not complicated or intricate and is therefore capable of being quickly grasped by the mind. Easy , on the other hand, points to that which requires little effort to do: a simple problem in long division; the easy job of preparing a meal from pre-cooked frozen foods. In popular usage the words are often used interchangeably and their connotations tend to become blurred: twelve easy lessons in Italian for the tourist; a task so simple that a child could perform it.

In its most precise sense, elementary is applied to rudiments or first principles, as of a branch of learning or of a skill, and is therefore concerned with basic or introductory material which may not necessarily be easy or simple: elementary electronics; elementary Greek. By extension, elementary is occasionally used as a synonym for simple in implying the absence of complexity, but here the meaning tends to merge with that of fundamental.

• Her poems deal with the elementary themes of nature; The television drama had the usual tiresome, elementary story line.

Facile and effortless both apply to that which is achieved, performed or activated with apparent ease. Facile was once a close synonym of easy but now carries somewhat derogatory overtones. It may describe that which is superficial in a bad sense or even spurious: the facile smile of the hard-sell salesman. Facile is also used of something which shows signs of having been done with too little expenditure of effort or with undue haste. It further suggests the careless or undisciplined use of skill or dexterity: a facile , flowing prose style in which the author has very little to say. Facile , in an extended sense, points also to glibness and thoughtlessness of speech: the facile tongue of the born gossip. Effortless , while it can mean making no effort or being passive, is more often used to describe action or activities which appear easy to perform, but whose smoothness conceals a mastery achieved by long practice and control: the pianist’s effortless playing of a difficult sonata; the trapeze artist’s effortless somersaulting forty feet in the air. Effortless may also refer to natural endowments impossible for others to emulate: the effortless climbing flight of the eagle; the spectacular, but effortless , leaps of the antelope.

Simplified means rendered less intricate or difficult and thus capable of being more easily understood, performed or used. The term presupposes an original condition of complexity that has been reduced to bare essentials: simplified English spelling in which the words are written as they sound; the teaching of fractions simplified by cutting apples into halves, thirds and quarters; a simplified process for making steel. Simplified may also have a pejorative meaning when used to describe something that suffers from being made simple to the point of distortion or uselessness: the candidate’s simplified , cliché-ridden suggestions for solving the complex problems of the poor. In most such instances the qualified term over-simplified is used.