NTS NAT key terms

The grammar rule that a verb must match its subject in number and person, so a singular subject takes a singular verb and a plural subject takes a plural verb.

A sentence construction in which the subject performs the action of the verb, as in 'The committee approved the plan', making the doer the focus of the sentence.

A construction where the subject receives the action and the doer may be omitted or placed after 'by', as in 'The plan was approved', shifting emphasis to the action or the result.

A group of words containing both a subject and a finite verb. An independent clause can stand alone as a sentence; a dependent clause cannot and must attach to a main clause.

A descriptive phrase placed so that it appears to modify the wrong word, usually because the intended subject is missing, as in 'Walking home, the rain started'.

The practice of expressing items in a list or comparison in the same grammatical form, such as all infinitives or all nouns, so the sentence reads smoothly and logically.

A word that has the same or nearly the same meaning as another word in a given context, such as 'begin' and 'start', though their shades of meaning often differ.

A word whose meaning is opposite to another word's meaning, such as 'hot' and 'cold'; graded antonyms allow degrees while complementary antonyms are absolute opposites.

A comparison that states a relationship between one pair of items and asks you to find or judge the same relationship in another pair, often written with colons.

Information in the surrounding words, sentence, or passage that helps a reader work out the meaning of an unfamiliar word without using a dictionary.

The emotional or cultural associations a word carries beyond its literal meaning, such as the positive tone of 'thrifty' compared with the negative tone of 'stingy'.

The literal, dictionary meaning of a word, considered apart from the feelings or associations the word may suggest to readers or listeners.

A comparison of two quantities by division, showing how many times one value contains another, often written as a fraction or with a colon.

An equation stating that two ratios are equal, used to solve problems in which quantities change together at a constant rate.

A way of expressing a number as a fraction of one hundred, so 25 percent means 25 out of every 100 parts of a whole.

The average found by adding all the values in a set and dividing the total by the number of values; it is strongly affected by extreme values.

The middle value of a data set arranged in order. If the set has an even number of values, the median is the average of the two middle values.

The value that appears most often in a data set; a set may have one mode, several modes, or no mode if all values occur equally often.

The smallest positive number that is a multiple of two or more given numbers, useful when adding fractions with different denominators.

A measure between zero and one of how likely an event is, calculated as the number of favourable outcomes divided by the number of equally likely possible outcomes.

A statement offered as a reason or piece of evidence in an argument, intended to support the conclusion; a premise may be true or false.

The statement an argument tries to establish, which should follow from the premises offered in support of it.

A form of deductive argument with two premises and a conclusion, where the conclusion follows if the premises are true, as in classic categorical reasoning.

An argument whose conclusion must be true whenever its premises are true, because of the logical form of the reasoning rather than the actual content.

A deductive argument that is both valid in form and has premises that are actually true, so its conclusion is guaranteed to be true.

A condition that must hold for something to occur, though it may not be enough on its own; without it, the outcome cannot happen.

A condition whose presence guarantees the outcome, even though the same outcome might also be produced by other conditions.

A single specific case that shows a general statement or argument to be false; one clear instance is enough to disprove a universal claim.

The logically equivalent form of a conditional statement obtained by swapping and negating both parts, so 'if P then Q' becomes 'if not Q then not P'.

A testable, specific prediction or proposed explanation that can be supported or rejected by observation and experiment rather than accepted on belief alone.

The factor that a researcher deliberately changes or selects in an experiment, in order to observe whether and how it affects the measured outcome.

The factor that is measured or observed in an experiment; its value is expected to change in response to the independent variable.

A standard unit from the International System of Units, such as the metre, kilogram, second, ampere, kelvin, mole, or candela, used for consistent scientific measurement.

The amount of substance containing as many elementary particles as there are atoms in 12 grams of carbon-12, roughly 6.02 × 10^23 particles.

A finite, ordered set of unambiguous steps for solving a problem or completing a task, which can be carried out mechanically and must eventually stop.

The economic model in which the quantity of a good that sellers offer and the quantity buyers want interact to set the price and quantity traded in a market.

The value of the best alternative given up when a choice is made, measured by what the same resources could otherwise have produced.