Morphology. What is morphology? Finite State Transducers Two Level Morphology. What is morphology?. Decomposition of words into meaningful units: anti dis establish ment arian ism Interacts with- syntax( categories and word order)
What is morphology?
Finite State Transducers
Two Level Morphology
lexical- semantic analysis
Why store all words as morphemes rather than all
Morphological combinations as words?
What does the morphological analyzer have to output?
CONCATENATIVE MORPHOLOGICAL PROCESSES:
INFIXATION: ( TAGALOG)
fikas - strong
fumikas - be strong
Kick + er
CIRCUMFIXATION: ( German)
ge [sag] t past prefix [say] past suffix
Regular vs Irregular
Jump/jumped hit/hit bring/brought sing/sang
adore/adorable, kick/kickable, fax/faxable
produce/production destroy/destruction *graft/graftuction
Irregular (English) Verbs
Store morphemes or words?
leben+ versicherung + gesellschaft+s+angesteller
life insurance company +Poss employee
Turkish verns have 40k forms
Agglutinative ( concatenative) languages are well behaved for FSAs
as long as we don’t include phonological or spelling changes
*hopp+ed hop, ???
The lexicon stores the lemmas, and divides them into adjective classes
State sequence indicates order of morpheme composition
e.g. comparative or adverb formation is by suffixation
Finite State Transducers (FSTs)- the Big Idea
Need to relate lexical level, the level that gives us the morphological
analysis (+plural,+able to the surface level that keeps track of
or graphological (spelling_ changes)
Q= finite set of states q0 to qn
finite alphabet of complex symbols (feasible pairs)
i:o with one symbol from the input alphabet
Q0 = the start state
F= set of final states
= (q, i:o) the transition function or matrixbetween
states. Takes a state from Q and a complex symbol
i:o from and returns a new state.
feasible pair: a relation of a symbol on one tape to a symbol
on the other tape.
e.g. can + [pl:^s]
trie: in lexicon, categories arranged by letter one at a time with
class at end. Allows parallel search as long as things match
e.g. m*e*t*a*l <N> m*e*t*a <root>
^ __ s #
e --> e /
Parse Example 1: unionizable
Parse Example 2: assess