inversion

Everyday

1. Turning something upside down or the other way round. tree →
2. (maths) Changing to the opposite or reverse, such as swapping the top and bottom of a fraction, or using the inverse operation. tree →
3. (grammar) Changing the usual order of words, like putting the verb before the subject in a question («Are you…?»). tree →
4. (weather) A temperature inversion: a layer of warm air over cold air near the ground that traps fog and smoke. tree →
5. (music) Changing the order of the notes in a chord. tree →

In the lessons

In maths it links to inverse operations (addition and subtraction undo each other) and to flipping fractions when dividing. In English grammar, questions and phrases like «Never have I seen…» use inversion. In science and geography, temperature inversions cause smog. On roller coasters, an inversion is a loop that turns riders upside down. Phrases: temperature inversion, word order inversion.

Examples

• The roller coaster has three inversions. tree →
• To divide by a fraction, we use inversion: 1/2 becomes 2/1. tree →
• «Are you ready?» uses inversion of the subject and the verb. tree →
• A temperature inversion trapped the smoke over the city. tree →
• The poem uses inversion to make the rhyme fit. tree →
• The pianist played the chord in its first inversion. tree →
• Inversion of colours turns black into white on the screen. tree →

Note

Countable or uncountable. Verb: invert; related adjective and noun: inverse. Trap: in maths «inverse» is the usual word for the opposite operation; «inversion» is the act of turning it over. Do not mix up with «invasion».