A valid query string in Coquery consists of one or more query item. Items are separated by spaces. The number of query items in a query string is not limited, but query duration increases with the number of items.
Query items are the smallest unit in a query string. Each query string has to contain at least one query item. The number of query items is not limited, but the time required to execute a query increases with the number of query items.
Query items are not case-sensitive: Walk, walk,
and WALK all specify the same query item. There are four
different types of query items. Word items, Transcription items, Lemma
items, and Gloss items.
Word items are used to match tokens in the corpus based on how they are
spelled. For example, the Word item walk matches all
tokens that are spelled walk. Word items are supported by all
corpora.
Transcription items are used to match tokens in the corpus based on their phonetic or phonological transcription. Slashes are used to distinguish Transcription items from Word items. The format of the transcription (e.g. International Phonetic Alphabet, SAMPA transcription symbols) may differ between corpora, and not all corpora provide phonetic or phonological transcriptions.
In order to match the token walk in the CMUdict Pronunciation
Dictionary, the Transcription item /W AO1 K/ is used. In the
CELEX Lexical Database, the token walk is matched by /'w$k/.
Lemma items are used to match tokens in the corpus that are assigned to
the same lemma. Square brackets are used to distinguish Lemma items from
Word items. For example, [walk] in CELEX matches the tokens
walk, walking, walks, and walked.
Gloss items are used to match tokens for which a gloss or a translation is available, for example in a dictionary corpus. Double quotation marks are used to mark gloss items.
If you want to restrict the matches of a query item to a particular
word-class, you can add a part-of-speech (POS) specifier to the query
item. POS specifiers are separated from the query item by a dot
., and consist of a POS tag enclosed in square brackets.
For example, walk.[nn1] matches all walk tokens in
the BNC that are tagged as singular nouns.
The set of available POS tags may differ between different corpora. For example, COCA uses the CLAWS7 tag set, while BNC uses CLAWS5. A list of the POS tags that are available in the active corpus can be displayed by first right-clicking on the part-of-speech column column in the Output column list, and then selecting “View unique values” from the context menu.
For convenience, and in order to retain syntactic compatibility with the
BYU syntax (see below), POS specifiers can also be used without providing
also a query item. Thus, [nn1] matches all tokens
tagged as singular nouns (NN1) in the BNC. Note that this syntax is
potentially ambiguous: For example, the tag POS is used in the BNC to
tag the possessive marker ‘s. At the same time, there are a few
tokens that have POS as their lemma. Similarly, articles in CLAWS7
are tagged by AT, which also exists as a lemma at. In the case of
such ambiguities between POS tags and lemmas, Coquery is compatible to
BYU-COCA and gives precedence to the part-of-speech tag.
Some corpora (e.g. the CMUdict Pronunciation Dictionary) are not tagged for part-of-speech. With these corpora, POS specifiers cannot be used.
In order to allow for partial matching, query items and POS specifiers
can contain any number of wildcard characters. There are two types of
wildcards characters: question marks ? and asterisks
*. They can be used within any query item type (i.e. Word,
Lemma, Transcription, Gloss), as well as within the tags of POS specifiers.
A question mark matches exactly one character. This wildcard character
can be used to match tokens with a specific length. For example, the
query item ? matches all words in the corpus that are
spelled using only a single character, for example I, the
numericals 1, 2, and so on, but also tokens that consist of
a single punctuation mark or a special character such as .,
_, or @. Similarly, the query item ??? matches
all tokens that consist of three characters, for example the,
web, 911, or :-).
If the query item contains other characters in addition to question mark
wildcards, the token has to match exactly the other characters, but can
have any character in the position of the wildcard. For example,
?alk matches in CELEX the tokens balk, calk,
talk, and walk, but not chalk or stalk. It
would also not match alk if that token existed in
CELEX.
The asterisk matches any number of characters, including zero and one.
A query item * consisting only of the asterisk wildcard will
match all tokens in the corpus. This can be useful in longer query
strings, or if the query item is restricted to a particular part of
speech (see below).
For example, w* matches any token that begins with the
character w. w*lk matches any token that begins with
the character w and ends with the character sequence lk,
e.g. walk, whelk, and waterfolk. w*l*k
matches any token that begins with the character w and ends in the
character k, and which also contains the character l in any
position. This item matches the same tokens as w*lk, but
also tokens such as warlock and woolsack.
In combination with POS specifiers, asterisk wildcards are particularly
useful to match only tokens that belong to a particular word-class. For
example, *.[n*] matches any token with a POS tag that starts
with n. In the BNC, this matches the singular noun walk
(tagged as NN1) as well as the plural noun walks (tagged as NN2).
If you want to query any character that has a special meaning in query
items (for example the wildcard characters, the square brackets, the
quotation mark, or the slashes), you must precede it by the ‘escape’
character \\ (the backslash). For example, if you want to match
all occurrences of the asterisk character in a corpus, you have to use the
query string \\*, because the unescaped asterisk * is interpreted as
a wildcard that matches any word.
The Coquery syntax allows query strings that match sequences of tokens in the corpus that differ in the number of tokens. This is done by appending to a query item, the range of occurrences that the query should match. The range is enclosed in curly brackets (similar to quantification in regular expressions).
For example, the query string the [n*]{1,3} [v*] any sequence of one, two,
or three nouns in the corpus that is preceded by the word the and followed
by a verb. In the current absence of a way that allows users to query phrasal
constituents in a corpus, this syntax can be used to construct queries that
approximate phrasal constructions. Many English noun phrases can be queried by
using the query string [DT]{0,1} [jj*|,]{0,6} [n*]{1,3} ~[n*]: this matches
any sequence of words that starts either with one or no determiner, followed
by a group of up to six tokens that can either be adjectives or commas,
followed by a group of one, two, or three nouns, followed by a word that is
not a noun.
The pipe symbol | acts as an OR operator. The OR operator is available for
all query types. The results table will contain the union of the matching
tokens. For example, walk|walked|walks matches either walk, walked,
walks, but not walking. [walk|talk] in CELEX matches the tokens walk, walking,
walks, and walked, as well as the tokens talk, talks, talking, and
talked.
Any query item can be prefixed by the hash mark #. This prefix indicates
that the matches of this query item will be lemmatized: instead of returning
only the exact matching tokens, all other forms that share the corresponding
lemma will be returned as well. For example, the query string #wrote will
match all tokens of the lemma WRITE, i.e. write, writes, writing,
wrote, and written.
/?/ matches all tokens with a transcription that consists of
only a single character.
The syntax of the query strings used by Coquery is modelled after the syntax used in the Bigham Young University web corpus interfaces such as COCA or BYU-BNC. A description of the BYU syntax can be found here: http://corpus.byu.edu/coca/help/syntax_e.asp
Most query strings that are valid in the BYU web interfaces are also
valid query strings in Coquery. However, where BYU-COCA uses
- to negate query items, Coquery uses the hash mark
#. Also, Coquery currently does not support synonym matching:
[=beat].[v*] matches verbs like hit, strike,
or defeat in BYU-COCA. In contrast, Coquery matches this query
string to all tokens that are tagged as verbs, and which are written as
=beat. Most likely, no token will be matched.
Coquery extends the BYU syntax by allowing for quantified query items. Also, Transcription queries are not supported by the BYU syntax.