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Morphology Dr. Radhika Mamidi. Why are we studying morphology? The knowledge of words will help us process language computationally at word level. Knowledge.

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Presentation on theme: "Morphology Dr. Radhika Mamidi. Why are we studying morphology? The knowledge of words will help us process language computationally at word level. Knowledge."— Presentation transcript:

1 Morphology Dr. Radhika Mamidi

2 Why are we studying morphology? The knowledge of words will help us process language computationally at word level. Knowledge of words include word structure and word formation rules. This knowledge will help us in developing tools like “Morphological Analyzers” and “Morphological Generators”.

3 What’s Morphology? The study of word structure The study of the mental dictionary:  How are words stored in the mind?  What is a possible word? Example: (i) At the supermarket, the girls bought pink cheeriots and the boys blue fistings. (ii) When their mother signaled, the girls barried home unhappily.

4 The words ‘fistings’ and ‘barried’ do not exist. However, assuming they are valid words of English, we ‘guess’ the meaning by context and the position of the word in the given sentence. We do this using our general knowledge and linguistic knowledge.

5 What do you know of cheeriots and fistings ? Part of speech = nouns [comes after adjectives] [-s ending] = more than one Meaning = some objects that have color [clue: supermarket] = some object that is sold; perhaps a toy The word forms are more like toys, balls, ribbons.

6 What do you know of barried Part of Speech = verb [position] [ends in –ed] = past tense Base form = barry Meaning = go The word form is more like carried, married.

7 What’s the Longest Word of English? Could it be ismestablishmentariandisanti ? Why not when antidisestablishmentarianism is possible. There is a systematic way of word formation. Possible words:  anti-missile (adjective)  anti-missile missile : a missile used for anti-missile purposes  anti- anti-missile missile missile : a missile used against anti- missile missiles  anti N missile N+1, where N can go until….

8 Morphemes Have a sound [form] and a meaning: Example: “cats”  /kaet/“four-legged animal”  /-s/“plural number”  Even though /-s/ has a sound and a meaning, it can’t mean “plural” by itself…  It has to attach to a noun

9 “A morpheme is the smallest unit of wordform that has meaning” Examples: cats = cat + -s girlish = girl + -ish unfriendly = un- + friend + -ly cat, -s, girl, -ish, un-, friend, -ly are morphemes

10 Even Bush knows morphology (…though he may use it differently than the rest of us)  The war on terrorism has transformationed the US- Russia Relationship  We’re working to help Russia securitize the dismantled warheads  The explorationists are only willing to help move equipment during the winter  This case has had full analyzation and has been looked at a lot

11 Compositionality “Explorationists” explore : to spend an extended effort looking around a particular area -ation : can attach to Verbs, the process of Xing -ist : can attach to Nouns, one who performs an action Y -s : attaches to Nouns, more than one Z explorationists : a compositional word Fully compositional meaning is based on its parts

12 Non-compositionality “Inflect” Is inflect morphologically complex? It contains more than one morpheme. What do in- and flect mean? This is a case of a non-compositional meaning. In explorationists, if you know the meaning of the parts, you know the meaning of the whole. Not necessarily so for inflect. Non-compositional meaning cannot be derived from its parts.

13 Lexical/Content words Words which are not function words are called content words or lexical words: these include nouns, verbs, adjectives, and most adverbs, though some adverbs are function words (e.g. then, why). They belong to open class. Dictionaries define the specific meanings of content words, but can only describe the general usages of function words. By contrast, grammars describe the use of function words in detail, but have little interest in lexical words.

14 Function words Function words or grammatical words are words that have little lexical meaning or have ambiguous meaning, but instead serve to express grammatical relationships with other words within a sentence. Function words may be prepositions, pronouns, auxiliary verbs, conjunctions, grammatical articles or particles, all of which belong to the group of closed class words.

15 To know about morpheme we should know about…. Free morphemes vs. Bound morphemes Lexical morphemes vs. Functional morphemes Null/Zero morpheme Inflectional morphemes vs. Derivational morphemes Root morphemes vs. Affix morphemes

16 Free vs Bound morphemes electr - and tox - have isolable meanings in electric, electrify, toxic, (de-)toxify But they cannot be pronounced on their own: they are bound morphemes girl and book have isolable meanings in girls, girlish, books, booked, booking They can occur on their own: they are free morphemes Are prefixes and suffixes bound morphemes?

17 Lexical morpheme Lexical free morphemes apple, smart, book, slow, eat, write, morning They can exist on their own as independent words. Lexical bound morphemes: -ceive, -ject, cran-, -ship, un- They cannot be used independently. They need another morpheme [free or bound] to form a word. Eg: re-ceive, con-ceive, sub-ject, pro-ject, cran-berry, scholar-ship, fellow-ship, un-kind, happi-ness

18 Functional morphemes Functional free morphemes: of, with, she, it, and, although, however, because, then Functional bound morphemes: -s, -s, -ed, -en, -ing cats, eats, played, eaten, playing

19 Four-way contrasts Lexical, Free: Nouns, Verbs, Adj, Adv cat, town, call, house, hall, smart, fast Lexical, Bound: including derivational affixes rasp- [raspberry], cran- [cranberry], -ceive [conceive, receive], un- [unhappy], re-[rewrite] Functional, Free: Prepositions, Articles with, at, and, an, the Functional, Bound: inflectional affixes -s, -ed, -ing, -en [eats, walked, laughing, eaten]

20 Exercise 1 Identify the free and bound morphemes in the following words walked, talked, danced, arrived playhouse, watchdog, football player drinking, playing, eating import, export, transport raspberry, cranberry invert, convert, divert Can the following words be decomposed? delight, news, traitor, bed, evening

21 Exercise 2 Identify the lexical and functional morphemes in the following words. Mention if they are free or bound. politically beautiful between writing raspberries unable nationalization

22 Inflection vs. Derivation Derivational suffixes: allow us to make new words  Mary is a writ er [write V – writer N ]  Mary writes for a liv ing [live V – living N ] Inflectional suffixes: required in order to make the sentence grammatical Inflected words belong to the same class  * Yesterday I walk to class [walk V – walked V ]  * I like all my student [student N – students N ]

23 Inflectional Morphology Examples: [the POS remains the same] VERBS EAT = eat, eats, ate, eaten, eating DRINK = drink, drinks, drank, drunk, drinking PLAY = play, plays, played, played, playing -s, -ed, -en, -ing are inflectional morphemes NOUNS PLAY = play, plays GIRL = girl, girls SHEEP = sheep, sheep -s, 0 are inflectional morphemes

24 Derivational morphology Two types: Can change the category {N,V,A,Adv} drive V +er = driver N eat v + able = eatable adj girl N + ish = girlish adj disturb V + ance = disturbance N Doesn’t have to change the category un + do V = undo V re+fry v = refry v un+happiness N = unhappiness N

25 Derivational – more examples Verbs eat – eatable [adj], eatables [noun] drink – drinking [noun] play – player [noun] -able, -ing, -er are derivational morphemes Nouns play – playful [adj], replay [verb] girl – girlish [adj], girlhood [noun] sheep – sheepish[adj] -ful, re-, -ish, -hood are derivational morphemes

26 Exercise 3 Each of the words below contains two morphemes – a root and a derivational affix. Decide if the derivational affix changes only the meaning or the class of the root as well. rewritehopeless happily unclearcreation happiness unhappyhelpful undo

27 Null/Zero morpheme a null morpheme is a morpheme that is realized by a phonologically null affix (an empty string of phonological segments) a null morpheme is an "invisible" affix It's also called zero morpheme; the process of adding a null morpheme is called null affixation,

28 Examples cat = cat + -0 = ROOT("cat") + SINGULAR cats = cat + -s = ROOT("cat") + PLURAL sheep = sheep + -0 = ROOT(“sheep") + SINGULAR sheep = sheep + -0 = ROOT(“sheep") + PLURAL

29 More examples darken[verb] = dark [adj] + -en Meaning = make more ‘Adjective’ redden [verb] = red + -en [make more Red] yellow [verb] = yellow + 0 [make more yellow] brown [verb] = brown + 0 [make more brown] blacken [verb] = black + -en [make more black]

30 Root Morphemes vs Affix morphemes Root morphemes are morphemes around which larger words are built. Root morphemes are free or bound. Affixes are additional morphemes added to roots to create multi- or poly-morphemic words. Affixes are always bound.

31 Rats Root = rat [free morpheme] Affix = -s [bound morpheme] Project Root = -ject [bound morpheme] Affix = pro- [bound morpheme] Mice Root = mouse [free morpheme] Affix = -s [bound morpheme] Ate Root = eat [free morpheme] Affix = -ed [bound morpheme] Disgracefulness Root = grace [free morpheme] Affixes = dis-, -ful, -ness [bound morpheme]

32 Affixes Morphemes added to free forms to make other free forms are called affixes. Mainly four kinds of affixes: 1. Prefixes (at beginning) – “un-” in “unable” 2. Suffixes (at end) – “-ed” in “walked” 3. Circumfixes (at both ends) – “en—en” in enlighten 4. Infixes (in the middle) – “-um-” in kumilad [‘to be red’], fumikas [‘to be strong’] [ kilad = ‘red’, fikas = ‘strong’ in Bontoc language] Affixes are bound morphemes.

33 Prefixes No prefix can determine the category of a complex word What does un- mean when it attaches to adjectives? unkind, unhappy What does un- mean when it attaches to verbs? undo, untie

34 Suffixes We can represent the fact that the rightmost suffix determines the category of a word for triplets like - rational, rationalize, rationalization  rational = adjective  rationalize = verb  rationalization = noun

35 Allomorph An allomorph is a variant form of a morpheme. The meaning remains the same, while the sound can vary. Example: the different forms of past tense morpheme /-ed/ [as we hear]  barked, hissed [t]  raised, smelled [d]  added, trotted [ed]

36 -s for nouns Example: the different forms of plural morpheme /-s/ are: [as we read] -s --- cats, dogs, boys, girls -es – watches, churches -0 – sheep /-s/, /-es/ and 0 are allomorphs of /-s/ {If pronunciation is considered, then /-s/, /-z/, /- iz/ and 0 are allomorphs of /-s/ in the above examples}

37 Hierarchical Structure within Words the word unlockable is ambiguous [[un + lock] able]: able to be unlocked [un [lock +able]]: not able-to-be-locked French History Teacher Old Ladies Hostel Old Bombay Highway

38 DisgracefulUngraceful Adj Adj / \/ \ Noun Suffix Prefix Adj / \| | / \ Prefix Noun| | Noun Suffix | || | | | Dis grace ful Un grace ful

39 Exercise 4 Give the hierarchical structure of the following words unwanted disfigurement interchangeable maladjusted actors retries unhappiness

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