Expression (linguistics) in the context of "Sentence (language)"

In linguistics and grammar, a sentence is a linguistic expression, such as the English example "The quick brown fox jumps over the lazy dog." In traditional grammar, it is typically defined as a string of words that expresses a thought, or as a unit consisting of a subject and predicate. In non-functional linguistics it is typically defined as a maximal unit of syntactic structure such as a constituent. In functional linguistics, it is defined as a unit of written texts delimited by graphological features such as upper-case letters and markers such as periods, question marks, and exclamation marks. This notion contrasts with a curve, which is delimited by phonologic features such as pitch and loudness and markers such as pauses; and with a clause, which is a sequence of words that represents some process going on throughout time.A sentence can include words grouped meaningfully to express a statement, question, exclamation, request, command, or suggestion.

A saying is any concise expression that is especially memorable because of its meaning or style. A saying often shows a wisdom or cultural standard, having different meanings than just the words themselves. Sayings are categorized as follows:

• Aphorism: a general, observational truth; "a pithy expression of wisdom or truth".
  • Proverb, adage or saw: a widely known or popular aphorism that has gained credibility by long use or tradition.
  • Apothegm/Apophthegm: "an edgy, more cynical aphorism; such as, 'Men are generally more careful of the breed of their horses and dogs than of their children.'"
• Axiom: a proposition that commends itself to general acceptance; a well-established or universally conceded principle; a maxim, rule, or law.
• Cliché or bromide: an unoriginal and overused saying.
  • Platitude: a cliché that is unsuccessfully presented as though it were meaningful, original, or effective.
• Epigram: a clever and often poetic written saying that comments on a specific person, idea, or thing; it especially denominates such a saying that is conspicuously put at the beginning of a text.
• Epitaph: a saying in honor of a decedent, often engraved on a headstone or plaque.
• Epithet: a descriptive word or saying already widely associated with a specific person, idea, or thing.
• Idiom or phraseme: a saying that has only a non-literal interpretation; "an expression whose meaning can't be derived simply by hearing it, such as 'kick the bucket.'"
  • Four-character idiom:
    • Chengyu: Chinese four-character idioms
    • Sajaseong-eo: Korean form of four-character idioms
    • Yojijukugo: Japanese form of four-character idioms
• Mantra: a religious, mystical, or other spiritual saying that is repeated, for example, in meditation.
• Maxim: (1) an instructional expression of a general principle or rule of morality or (2) simply a synonym for "aphorism"; they include:
  • Brocard
  • Gnome
  • Legal maxim
• Motto: a saying used frequently by a person or group to summarize its general mission.
  • Credo: a motto implicitly or explicitly extended to express a larger belief system.
  • Slogan: a motto with the goal of persuading.
• Quip: a clever or humorous saying based on an observation.
• Witticism: a saying that is clever and usually humorous and that is notable for its form or style just as much as, or more than, its meaning.

"Is the glass half empty or half full?", and other similar expressions such as the adjectives glass-half-full or glass-half-empty, are idioms which contrast an optimistic and pessimistic outlook on a specific situation or on the world at large. "Half full" means optimistic and "half empty" means pessimistic. The origins of this idea are unclear, but it dates at least to the early 20th century. Josiah Stamp is often given credit for introducing it in a 1935 speech, but although he did help to popularize it, a variant regarding a car's gas tank occurs in print with the optimism/pessimism connotations as early as 1929, and the glass-with-water version is mentioned simply as an intellectual paradox about the quantity of water (without reference to optimism/pessimism) as early as 1908.

In linguistics, a pro-form is a type of function word or expression that stands in for (expresses the same content as) another word, phrase, clause or sentence where the meaning is recoverable from the context. They are used either to avoid repetitive expressions or in quantification (limiting the variables of a proposition).

Pro-forms are divided into several categories, according to which part of speech they substitute: