View source for Irish/Using Nua-Chorpas na hÉireann

The [https://corpas.focloir.ie ''New Corpus for Ireland'' or ''Nua-Chorpas na hÉireann''] (or ''the Foclóir corpus'') is a very useful tool for checking how some things are phrased in Irish and which expressions are used by native speakers and which ones are not. Unfortunately the corpus’s help page is not accessible and the UI isn’t very user-friendly. One can find some documentation for the software used there, but it’s not corpas-specific and thus not very helpful when working with this particular corpus of Irish.

This page isn’t meant to be a comprehensive documentation of the corpus, but at least a list of hints that would make your work with the corpus a bit more efficient. For more comprehensive documentation, see [[#External documentation|external links]] below.

== First steps ==
To use the corpus, you first have to create an account using the [https://focloir.sketchengine.co.uk/run.cgi/register_form registration form]. Registration is free, but you will have to wait until your account is accepted before you’ll be able to log in and use the corpus.

=== Old and new interface ===

When you log in, you’ll see the old Sketch Engine web interface. You can use it but it is also possible to access the new interface by logging into [https://focloir.sketchengine.eu focloir.sketchengine.eu] instead. The new interface is generally much more user-friendly (and compatible with the official Sketch Engine documentation) but '''beware''': some features don’t work with it (for example ''word sketches'' work in the old interfaces, but they don’t in the new one).

You can follow this guide in the old interface, unless it refers explicitly to the new one.

== Simple querying ==
When you log into the corpus, you’ll see the ⟨Home⟩ (⟨Leathanach Tosaigh⟩) screen with an input form to perform a ''simple search''. As the prompt says, you can type words or phrases in there. If you type a ''lemma'' form of a word (ie. the base form that you’d find in a dictionary), it will search for any occurrence of that word in any form in the corpus. And it will treat every word in a phrase this way.

This means that if you type <code>bí madra ag</code> (‘to be, dog, at’), you’ll see results such as:
* ''bhí madra agamsa'' ‘I had a dog’,
* ''tá madraí aige siúd'' ‘that one has dogs’, etc.

You’ll also see the number of all results at the top (''Hits: 31'' or ''Amas: 31'').

If a word you type in is ''not'' a lemma form, only sentences that match this form exactly will be found. So if you type <code>bí '''madraí''' ag</code> (‘to be, '''dogs''', at’), you’ll get results like:
* ''Beidh madraí ag Waterloo'' ‘there will be dogs at Waterloo’,
* ''tá madraí aige siúd'' ‘that one has dogs’,
but no instances of singular ''madra'' (and you’ll see that the number of results fell down to 8).

The default search is case-insensitive, you can type both <code>madraí</code> or <code>MADRAÍ</code> and you’ll get the same set of results.

<div class="warningbox">'''Note!''' The way words in the corpus are tagged with their lemma form and part-of-speech is not perfect. You’ll have to write the exact form you’ll looking for sometimes – often you won’t find non-standard historical and dialectal forms when using the lemma form. For example the ''dative plural'' forms like ''Gaelaibh'', ''fearaibh'', ''cosaibh'' (and their lenited counterparts) are interpreted by the corpus as their own '''singular''' lemmata.</div>

=== Wildcards (new interface only) ===

If you use [[#Old and new interface|the new interface]], you can perform simple searches in the ⟨Concordance⟩ tab with ⟨Simple⟩ query type chosen.
You can use wildcard characters:
* <code>*</code> standing for any number of characters,
* <code>?</code> for any single character in your queries,
* <code>|</code> meaning ''or'', allowing you to list various words or forms,
* [https://www.sketchengine.eu/guide/regular-expressions/#toggle-id-1 and some more].

Thus you can for example type <code>bí * ag</code> and get all occurences of the verb ''bí'' and its forms (''tá, raibh, beidh'', etc.) followed by any word, followed by any form of the preposition ''ag'', thus you’ll get a result list containing:
* ''tá feidhm ag na fóralach cosúlacha…'',
* ''… nach raibh feidhm aige…'',
* ''Ceangaltais a bheidh déanta ag an gComhphobal'', etc.

You can also type just a part of the word, eg. <code>feoil*</code> will find occurrences of every word starting with ''feoil'' and whose lemma starts with ''feoil'', those the list will include: ''feoil'', ''feola'', ''feoilséantóir'', ''mhuicfheoil'' (it’s lemmatized as ''feoil''), ''feoilmhian'', etc. If you type <code>Ga?l</code> you’ll get results for both ''Gael'' and ''Gall'' (and also ''gaol'' and ''gail'').

You can use the <code>|</code> to list multiple words or phrases that are supposed to match in your query, eg. if you type <code>snámh|léamh</code> you’ll find all instances of the verbal nouns ''snámh'' ‘swimming’ and ''léamh'' ‘reading’, if you type <code>bí snámh ag|bí léamh ag</code> you’ll find all instances of the ''tá {{smallcaps|⟨verbal noun⟩}} agam'' ‘I can {{smallcaps|⟨verb⟩}}’ construction with the verbal nouns for ‘swim’ and ‘read’, regardless of tense or grammatical person.

=== Filtering the results ===
If you want to filter the results using criteria like ''texts written only by native speakers'' or ''only Munster Irish'', you need to enter the ''Concordance'' screen. To do that you need to click ⟨>> More⟩ (⟨>> Tuilleadh⟩) under the results list, then in the menu on the left click ⟨Filter⟩ (⟨Scagaire⟩), and that will bring you to a screen where you can select your filtering criteria and confirm them by clicking ⟨Filter Concordance⟩ (⟨Déan an Comhchordacht a Scagadh⟩). This will take you to the concordance results screen with the results filtered.

== CQL ==
If you require more power – you want to find utterances matching complex patterns – you can always reach for ''CQL'' by entering the ⟨Concordance⟩ (⟨Comhchordacht⟩) tab and switching the query type to ⟨CQL⟩.

The Corpus Query Language (CQL) allows you to make complex [https://en.wikipedia.org/wiki/Regular_expression regex]-like queries, including things like looking for phrases containing specific parts of speech or inflectional forms – that’s possible because every word in the corpus is tagged with information about its part-of-speech and inflectional form. Using CQL is more complex than simple searching for words, but it enables you to be much more flexible in your searches.

Every single token (word or punctuation mark) in the Foclóir corpus has multiple attributes with text values associated with it. CQL allows you to query values of those attributes. The available attributes are:
* <code>word</code> – the word itself, verbatim as it appears in the text,
* <code>lc</code> (''word (lowercase)'') – the word but with all uppercase characters changed to lowercase,
* <code>lemma</code> – the ''lemma'', ie. the base dictionary form of the word,
* <code>lemma_lc</code> (''lemma (lowercase)'') – the lemma with all characters changed to lowercase,
* <code>tag</code> – the part-of-speech tag with inflectional information for the word,
* <code>lempos</code> – lemma and a single character representing the part-of-speech, separated with a dash.

For example the sentence-initial verb ''Tá'' ‘is’ will have its <code>word</code> value equal to <code>Tá</code>, <code>lc</code>=<code>tá</code>, <code>lemma</code>=<code>bí</code>, <code>lemma_lc</code>=<code>bí</code>, <code>tag</code>=<code>Vmip</code>, <code>lempos</code>=<code>bí-v</code>. Some details of the <code>tag</code> format will be explained later. Most words will have their <code>lemma</code> and <code>lemma_lc</code> values equal, but some words that are typically written with initial capital will have those two different (eg. ''Éireannach'' ‘an Irishman’ has <code>lemma</code>=<code>Éireannach</code> and <code>lemma_lc</code>=<code>éireannach</code>).

The general most basic element of CQL queries is a pair of square brackets matching a token: <code>[]</code> – this means ‘any word or punctuation mark’. You can add a condition in a form <code>attribute = "value-regex"</code> inside the bracket to limit what the query will match.

For example the query <code>[lemma="bí"]</code> will match every occurrence of any form of the verb ''bí'' (the results will be the same as when typing <code>bí</code> in the simple search). The query <code>[word="bí"]</code> will find all instance of all-lowercase ''bí'' (and only ''bí'', not any other form) in the corpus – this is impossible to get using the simple query.

When you type <code>attribute = "value"</code> the value is treated as a regex, so you can for example write <code>[word = "dra((ío)|(oidhea))cht"]</code> to find all occurrences of both – the old (''draoidheacht'') and new (''draíocht'') – spellings of the word ''draíocht'' ‘magic, witchcraft, druidism’. You can also type <code>[word = ".*nnach[td]"]</code> to find all the words ending in ''-nnacht'' or ''-nnachd''.

Thus, to find all instances of the ''tá {{smallcaps|⟨verbal noun⟩}} agam'' ‘I can {{smallcaps|⟨verb⟩}}’ construction with any form of the verb ''tá'', for any grammatical person, with the verbal nouns ''snámh'' ‘swim’ and ''léamh'' ‘read’ (including old spelling ''léigheamh''), you can write:

:<pre>[lemma = "bí"] [lc = "snámh|lé(ighe)?amh"] [lemma = "ag"]</pre>

(which at the time of writing doesn’t find any instance with the old spelling, only ''snámh'' and ''léamh'').

You can omit the brackets and attribute name for the ''default'' attribute, so for example if you choose ⟨Default attribute⟩ (⟨Aitreabúid réamhshocraithe⟩) in your search to be ⟨word (lowercase)⟩, you can shorten the above to:

:<pre>[lemma = "bí"] "snámh|lé(ighe)?amh" [lemma = "ag"]</pre>

If you want to search for a specific string without treating it as a regex, you can use double equals sign <code>==</code>, for example <code>[word == "."]</code> will find all the instances of the period punctuation mark.

You can combine multiple conditions and perform Boolean logic on them using the following operators: <code>&</code> (and), <code>|</code> (or), <code>!</code> (not), and group them with parentheses <code>( )</code>. So, given the information that adjectives in the corpus have <code>tag</code>s beginning with the letter <code>A</code>, you can find all correctly tagged sequences of two consecutive adjectives with lenition marked in writing with:

:<pre>[word = "[cptgbdm]h.*" & tag = "A.*"] [word = "[cptgbdm]h.*" & tag = "A.*"]</pre>
(or using the <code>lempos</code> attribute as <code>[lempos = "[cptgbdm]h.*-j"] [lempos = "[cptgbdm]h.*-j"]</code>, don’t ask me why adjectives have ''-j'' there).

You can also a question mark <code>?</code> after a token to mark it as optional, and braces with two numeric values: <code>{x, y}</code> to say that you want the given token query to match between <code>x</code> and <code>y</code> times.

For example to find most instances of the construction ''is maith/fearr liom {{smallcaps|⟨verbal noun phrase⟩}}'' ‘I like/prefer to {{smallcaps|⟨infinitive phrase⟩}}’, regardless of person (''liom'', ''leat'', ''leis an bhfear''…) or whether the verbal noun has an object (''arán a ithe'' ‘to eat bread’) or not (''snámh'' ‘to swim’), you could write something like:

:<pre>[tag = "W.*"] [lemma = "maith"] [lemma = "le"] ([tag = "(T|D).*"]? [tag = "N.*"] [tag = "A.*"]{0,5} [tag = "D.*"]?)? ([tag = "Dp.*"] | ([tag = "(T|D).*"]? [tag = "N.*"] [tag = "A.*"]{0,5} [tag = "D.*"]? [word = "a|do"]) | ([word = "mé|t(h)?ú|é|í|sinn|sibh|iad"] [word = "a|do"]))? [tag = "Nv.*"]</pre>

Let’s break this monstrosity down into parts:
* <code>[tag = "W.*"]</code> – the copula, it has tags beginning in ''W'',
* <code>[lemma = "maith"]</code> – the adjective ''maith'' or any of its forms (lenited ''mhaith'', comparative ''f(h)earr'', etc.),
* <code>[lemma = "le"]</code> – the preposition ''le'' or any of its forms (''leis'', ''liom'', etc.),
* <code>( … )?</code> – optionally a group representing a noun phrase subject, containing:
:* <code>[tag = "(T|D).*"]?</code> – either an article (''an'', ''na''), tags beginning with ''T'' or a determiner (like possessive ''mo'', ''a'', etc.) – tags beginning in ''D'',
:* <code>[tag = "N.*"]</code> – a noun,
:* <code>[tag = "A.*"]{0, 5}</code> – zero up to five adjectives,
:* <code>[tag = "D.*"]?</code> – an optional following determiner (like ''seo'' or ''sin''),
* <code>( … )?</code> – optionally a group representing the direct object, containing:
:* <code> … | … | … </code> – either:
::* <code>[tag = "Dp.*"]</code> – a possessive pronoun (''mo'' ‘my’, ''do'' ‘your’, ''a'' ‘his/her/their’, etc.),
::* or <code>( … )</code> – another noun phrase group:
:::* <code>[tag = "(T|D).*"]? [tag = "N.*"] [tag = "A.*"]{0,5} [tag = "D.*"]?</code> – article, noun, adjectives, determiner, like before,
:::* <code>[word = "a|do"]</code> – the particle ''a'' (or its older form ''do'') verbatim after the direct object,
::* or <code>([word = "mé|t(h)?ú|é|í|sinn|sibh|iad"] [word = "a|do"])</code> – a pronoun object followed by ''a'' or ''do'',
* <code>[tag = "Nv.*"]</code> – finally, the verbal noun.

This query still doesn’t catch everything (it doesn’t allow any genitive attributes in the noun phrases, for example) – but it shows the flexibility you get with CQL.

To learn more visit the official guide to Corpus Query Language linked [[#External documentation|below]].

=== POS-tags ===
'''TODO'''

== External documentation ==
* [https://www.sketchengine.eu/gaeilge-tagset/ Irish tagset – extensive list of part-of-speech tags available in the corpus]
* [https://www.sketchengine.eu/guide/ Sketch Engine User Guide] – a guide to newer version of the software the ''Corpas'' is using. The graphical interface presented in the guide is completely different to what you’ll find on corpas.focloir.ie, but the principles described there will generally be valid for the ''Corpas'' too. Among things you’ll find there are:
:* [https://www.sketchengine.eu/documentation/corpus-querying/ Guide to CQL]
:* [https://www.sketchengine.eu/guide/regular-expressions/ Description of Sketch Engine regex syntax]

[[Category:Text corpora]]
[[Category:Tool guides]]
[[Category:Irish]]