These words share the implication that something already in existence is being newly brought to light. Find and discover can both be used for an accidental or gratuitous gaining of knowledge; of the two, find is the less formal.

• Explorers in Australia discovered flora and fauna found nowhere else in the world.

Both can, of course, be used to describe an intentional effort; find in this case may imply either a search for something new or the discovering of something lost but previously possessed.

• He finally found the missing keys in a jacket he had put away for the summer; We know there must be a law that governs the odd gravitation behaviour of certain stars, but it may take us decades to find it.

Discover , when it implies an intentional search, always suggests the acquiring of something that already exists but is new to the discoverer: Mendel raised crop after crop of snapdragons to discover the laws governing heredity. It should be noted that this sense of discover contrasts sharply with invent, words often confused.

• Gilbert discovered electricity, but Edison invented the electric light bulb.

Learn , unearth and detect are equally able to suggest either intentional or accidental discovery, although they tend more strongly towards the former. Of the three, learn is the most general and informal, detect the most specific and formal. Learn in one sense can imply a minimum of effort in gaining unsought knowledge: It was only today I happen to learn the name of the song I’d been whistling for year. But the weight of usage here is on conscious, painstaking effort towards a predetermined goal: A pianist learns the secret of a major work only by practising it intensively over a long period of time. Unearth , when referring to accidental discovery, implies the rediscovery of something lost or obscured by the passage of time: In his researches he was startled to unearth the manuscript of a major work by Boswell, never before published. Again, the suggestion of deliberate search is more frequently present, in which case digging deep into a subject is suggested: The prosecutor swore he would unearth the real facts in the case if he had to question everyone who had known the dead man. Detect is more rarely applicable to accidental discovery: To his surprise, he detected a bright red glow emanating from a crater in the moon. It most often suggests deliberate, deductive investigation and the making of extremely precise observations: Her pulse was so weak and erratic that the doctor could barely detect it. In one use, the word has a sharply negative sense that contrasts with a positive use of discover : It may take time for the public to discover your real worth as a writer, but fortunately the vapidity of the work has been quickly detected .

Determine , ascertain and locate are almost exclusively suggestive of deliberate search and discovery . Determine , in facts, is charged with the suggestion of painstaking conscious effort, especially to resolve a controversy.

• From the facts presented, the coroner was able to determine conclusively that the death was not a suicide; No student may leave until he can determine the acidity or alkalinity of he chemical placed before him.

Ascertain implies that the searcher began with an awareness of his lack of knowledge on a given matter and worked to correct it; in this it is similar to but much more formal than determine ?even to the point of pomposity, except in very technical, legal or scientific writing.

• We shall probably never be able to ascertain the exact nature of these sub-atomic particles; With careful research, it is possible to ascertain the often unspoken assumptions held by people of a particular historical era.

Locate is more specialized in meaning than either determine or ascertain , usually implying the fixing of an occurrence or thing in space.

• All efforts have failed to locate decisively the birthplace of Columbus; From his directions, it shouldn’t be difficult to locate the beach house, even though you’ve never been there before.