Word formation processes: Ways of creating new words in English
1. Affixation: adding a derivational affix to a word. Examples: abuser, refusal, untie, inspection, pre-cook.
2. Compounding: joining two or more words into one new word. Examples: skateboard, whitewash, cat lover, self-help, red-hot, etc.
3. Zero derivation: (also called conversion or functional shift): Adding no affixes; simply using a word of one category as a word of another category. Examples: Noun-verb: comb, sand, knife, butter, referee, proposition.
4. Stress shift: no affix is added to the base, but the stress is shifted from one syllable to the other. With the stress shift comes a change in category.
Noun Verb
cómbine combíne
ímplant implánt
réwrite rewríte
tránsport transpórt
Noun Adjective
cóncrete concréte
ábstract abstráct
5. Clipping: shortening of a polysyllabic word. Examples: bro (<>
6. Acronym formation: forming words from the initials of a group of words that designate one concept. Usually, but not always, capitalized. An acronym is pronounced as a word if the consonants and vowels line up in such a way as to make this possible, otherwise it is pronounced as a string of letter names. Examples: NASA (National Aeronautics and Space Administration), NATO (North Atlantic Treaty Organization), AIDS (Acquired Immune Deficiency Syndrome), scuba (self-contained underwater breathing apparatus), radar (radio detecting and ranging), NFL (National Football League), AFL-CIO (American Federation of Labor-Congress of Industrial Organizations).
7. Blending: Parts (which are not morphemes!) of two already-existing words are put together to form a new word. Examples: motel (motor hotel) brunch (breakfast & lunch), smog (smoke & fog), telethon (television & marathon), modem (modulator & demodulator), Spanglish (Spanish & English).
8. Backformation: A suffix identifiable from other words is cut off of a base which has previously not been a word; that base then is used as a root, and becomes a word through widespread use. Examples: pronunciate (<>phonological part of the word which is not interpretable as an affix or word is cut off (e.g. the '-essor' of 'professor' is not a suffix or word; nor is the '-ther' of 'brother'. In backformation, the bit chopped off is a recognizable affix or word ('ham ' in 'hamburger'), '-ion' in 'self-destruction'. Backformation is the result of a false but plausible morphological analysis of the word; clipping is a strictly phonological process that is used to make the word shorter. Clipping is based on syllable structure, not morphological analysis. It is impossible for you to recognize backformed words or come up with examples from your own knowledge of English, unless you already know the history of the word. Most people do not know the history of the words they know; this is normal.
9. Adoption of brand names as common words: a brand name becomes the name for the item or process associated with the brand name. The word ceases to be capitalized and acts as a normal verb/noun (i.e. takes inflections such as plural or past tense). The companies using the names usually have copyrighted them and object to their use in public documents, so they should be avoided in formal writing (or a lawsuit could follow!) Examples: xerox, kleenex, band-aid, kitty litter.
10. Onomatopoeia (pronounced: 'onno-motto-pay-uh'): words are invented which (to native speakers at least) sound like the sound they name or the entity which produces the sound. Examples: hiss, sizzle, cuckoo, cock-a-doodle-doo, buzz, beep, ding-dong.
11. Borrowing: a word is taken from another language. It may be adapted to the borrowing language's phonological system to varying degrees. Examples: skunk, tomato (from indigenous languages of the
3.5.1 Basic Notions of Semantics
A perennial problem in semantics is the delineation of its subject matter. The term meaning can be used in a variety of ways, and only some of these correspond to the usual understanding of the scope of linguistic or computational semantics. We shall take the scope of semantics to be restricted to the literal interpretations of sentences in a context, ignoring phenomena like irony, metaphor, or conversational implicature
A standard assumption in computationally oriented semantics is that knowledge of the meaning of a sentence can be equated with knowledge of its truth conditions: that is, knowledge of what the world would be like if the sentence were true. This is not the same as knowing whether a sentence is true, which is (usually) an empirical matter, but knowledge of truth conditions is a prerequisite for such verification to be possible. Meaning as truth conditions needs to be generalized somewhat for the case of imperatives or questions, but is a common ground among all contemporary theories, in one form or another, and has an extensive philosophical justification,
A semantic description of a language is some finitely stated mechanism that allows us to say, for each sentence of the language, what its truth conditions are. Just as for grammatical description, a semantic theory will characterize complex and novel sentences on the basis of their constituents: their meanings, and the manner in which they are put together. The basic constituents will ultimately be the meanings of words and morphemes. The modes of combination of constituents are largely determined by the syntactic structure of the language. In general, to each syntactic rule combining some sequence of child constituents into a parent constituent, there will correspond some semantic operation combining the meanings of the children to produce the meaning of the parent.
3.5.2 Practical Applications of Semantics
Some natural language processing tasks (e.g., message routing, textual information retrieval, translation) can be carried out quite well using statistical or pattern matching techniques that do not involve semantics in the sense assumed above. However, performance on some of these tasks improves if semantic processing is involved. (Not enough progress has been made to see whether this is true for all of the tasks).
Some tasks, however, cannot be carried out at all without semantic processing of some form. One important example application is that of database query, of the type chosen for the Air Travel Information Service (ATIS) task For example, if a user asks, ``Does every flight from London to San Francisco stop over in Reykyavik?'' then the system needs to be able to deal with some simple semantic facts. Relational databases do not store propositions of the form every X has property P and so a logical inference from the meaning of the sentence is required. In this case, every X has property P is equivalent to there is no X that does not have property P and a system that knows this will also therefore know that the answer to the question is no if a non-stopping flight is found and yes otherwise.
Any kind of generation of natural language output (e.g., summaries of financial data, traces of KBS system operations) usually requires semantic processing. Generation requires the construction of an appropriate meaning representation, and then the production of a sentence or sequence of sentences which express the same content in a way that is natural for a reader to comprehend,. To illustrate, if a database lists a 10 a.m.\ flight from London to Warsaw on the 1st--14th, and 16th--30th of November, then it is more helpful to answer the question What days does that flight go? by Every day except the 15th instead of a list of 30 days of the month. But to do this the system needs to know that the semantic representations of the two propositions are equivalent.
3.5.3 Development of Semantic Theory
It is instructive, though not historically accurate, to see the development of contemporary semantic theories as motivated by the deficiencies that are uncovered when one tries to take the FOPC example further as a model for how to do natural language semantics. For example, the technique of associating set theoretic denotations directly with syntactic units is clear and straightforward for the artificial FOPC example. But when a similar programme is attempted for a natural language like English, whose syntax is vastly more complicated, the statement of the interpretation clauses becomes in practice extremely baroque and unwieldy, especially so when sentences that are semantically but not syntactically ambiguous are considered. For this reason, in most semantic theories, and in all computer implementations, the interpretation of sentences is given indirectly. A syntactically disambiguated sentence is first translated into an expression of some artificial logical language, where this expression in its turn is given an interpretation by rules analogous to the interpretation rules of FOPC. This process factors out the two sources of complexity whose product makes direct interpretation cumbersome: reducing syntactic variation to a set of common semantic constructs; and building the appropriate set-theoretical objects to serve as interpretations.
The first large scale semantic description of this type was developed by Montague made a further departure from the model provided by FOPC in using a more powerful logic (intensional logic) as an intermediate representation language. All later approaches to semantics follow Montague in using more powerful logical languages: while FOPC captures an important range of inferences (involving, among others, words like every, and some as in the example above), the range of valid inference patterns in natural languages is far wider. Some of the constructs that motivate the use of richer logics are sentences involving concepts like necessity or possibility and propositional attitude verbs like believe or know, as well as the inference patterns associated with other English quantifying expressions like most or more than half, which cannot be fully captured within FOPC
For Montague, and others working in frameworks descended from that tradition (among others, Partee, e.g., Krifka, and Groenendijk and Stokhof, the intermediate logical language was merely a matter of convenience which could in principle always be dispensed with provided the principle of compositionality was observed. (I.e., The meaning of a sentence is a function of the meanings of its constituents, attributed to Frege, For other approaches, (e.g., Discourse Representation Theory, an intermediate level of representation is a necessary component of the theory, justified on psychological grounds, or in terms of the necessity for explicit reference to representations in order to capture the meanings of, for example, pronouns or other referentially dependent items, elliptical sentences or sentences ascribing mental states (beliefs, hopes, intentions). In the case of computational implementations, of course, the issue of the dispensability of representations does not arise: for practical purposes, some kind of meaning representation is a sine qua non for any kind of computing.
3.5.4 Discourse Representation Theory
Discourse Representation Theory (DRT) as the name implies, has taken the notion of an intermediate representation as an indispensable theoretical construct, and, as also implied, sees the main unit of description as being a discourse rather than sentences in isolation. One of the things that makes a sequence of sentences constitute a discourse is their connectivity with each other, as expressed through the use of pronouns and ellipsis or similar devices. This connectivity is mediated through the intermediate representation, however, and cannot be expressed without it.
Dynamic semantics (e.g., takes the view that the standard truth-conditional view of sentence meaning deriving from the paradigm of FOPC does not do sufficient justice to the fact that uttering a sentence changes the context it was uttered in. Deriving inspiration in part from work on the semantics of programming languages, dynamic semantic theories have developed several variations on the idea that the meaning of a sentence is to be equated with the changes it makes to a context.
Update semantics approaches have been developed to model the effect of asserting a sequence of sentences in a particular context. In general, the order of such a sequence has its own significance. A sequence like:
Someone's at the door. Perhaps it's John. It's Mary!
is coherent, but not all permutations of it would be:
Someone's at the door. It's Mary. Perhaps it's John.
Recent strands of this work make connections with the artificial intelligence literature on truth maintenance and belief revision
Dynamic predicate logic extends the interpretation clauses for FOPC (or richer logics) by allowing assignments of denotations to subexpressions to carry over from one sentence to its successors in a sequence. This means that dependencies that are difficult to capture in FOPC or other non-dynamic logics, such as that between someone and it in:
Someone's at the door. It's Mary.
can be correctly modeled, without sacrificing any of the other advantages that traditional logics offer.
3.5.6 Situation Semantics and Property Theory
One of the assumptions of most semantic theories descended from Montague is that information is total, in the sense that in every situation, a proposition is either true or it is not. This enables propositions to be identified with the set of situations (or possible worlds) in which they are true. This has many technical conveniences, but is descriptively incorrect, for it means that any proposition conjoined with a tautology (a logical truth) will remain the same proposition according to the technical definition. But this is clearly wrong: all cats are cats is a tautology, but The computer crashed, and The computer crashed and all cats are cats are clearly different propositions (reporting the first is not the same as reporting the second, for example).
Situation theory has attempted to rework the whole logical foundation underlying the more traditional semantic theories in order to arrive at a satisfactory formulation of the notion of a partial state of the world or situation, and in turn, a more satisfactory notion of proposition. This reformulation has also attempted to generalize the logical underpinnings away from previously accepted restrictions (for example, restrictions prohibiting sets containing themselves, and other apparently paradoxical notions) in order to be able to explore the ability of language to refer to itself in ways that have previously resisted a coherent formal description
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