DepPattern and Pattern Grammar

DepPattern is a formalism combining notions of both Dependency Grammar and Pattern Grammar.

The main aim of Pattern Grammar is to identify meaningful patterns associated to words. The meaningful patterns of a word can be defined as all the words and structures which are regularly associated with the word and which contribute to its meaning. A meaninful pattern is identified if a combination of words occurs relatively frequently, if it is dependent on a particular word choice, and if there is a clear meaning associated with it. One of the most relevant assumpations of Pattern Grammar is that there is no a clear boderline between both syntactic and lexical structures.

A very simple formalism is used to represent meaningful patterns of words in Pattern Grammar. For instance, the meaningful patterns of the verb “explain” would be represented as follows:

V n	(explain all the different types)
V wh	(explained how it worked)
V about n	(explain about the barman)
V n to n	(she explained it to you)
V that	(she explained that she never paid)
V to n	(Alex explained to me)
V to n that	(have to explain to their patients that they...)

Where V stands for the lexical item to be represented (in this case “explain”), symbols 'n', 'wh', 'that' stands for 'noun group', 'clause introduced by a wh-word', and 'clause introduced by that', respectively. Finally, to and about are other lexical items being part of a pattern.

DepPattern is provided with the approppriate tools to represent and identify meaningful patterns of lexical words. In order to identify such meaningful patterns in DepPattern, we need to introduce dependency relationships between words instead of phrasal groups. The specific DepPattern rules written to identify the meaningful patterns of “explain” could be the following:

V n	DobjR: VERB<lemma:explain> NOUN
V wh	ObjL: [VERB<lemma:explain>] PRO<type:W> [X]* VERB
	NEXT
	DObjR: VERB<lemma:explain> [PRO<type:W>] [X]* VERB
V about n	PrepCompR: VERB<lemma:explain> PRP<lemma:about> NOUN
V n to n	DobjR: VERB<lemma:explain> NOUN [PRP<lemma:to>] [NOUN]
	NEXT
	PrepCompR VERB<lemma:explain> [NOUN] PRP<lemma:to> NOUN
V that	SpecL: [VERB<lemma:explain>] CONJ<lemma:that> [X]* VERB
	NEXT
	DObjR VERB<lemma:explain> [CONJ<lemma:that>] [X]* VERB
V to n	PrepCompR: VERB<lemma:explain> PRP<lemma:about> NOUN
V to n that	SpecL: [VERB<lemma:explain>] [PRP<lemma:to>] [NOUN] CONJ<lemma:that> [X]* VERB
	NEXT
	PrepCompR: VERB<lemma:explain> PRP<lemma:to> NOUN [CONJ<lemma:that>] [X]* [VERB]
	NEXT
	DobjR: VERB<lemma:explain> [PRP<lemma:to>] [NOUN] [CONJ<lemma:that>] [X]* VERB

These rules should be located at the begining of the verbal phrase layer, and following adverb, adjective, and nominal rules.