Developed at the
University of Lisbon, Dept. of Informatics,
NLX-Natural Language and Speech Group.
Table of contents
LX-Conjugator (beta version) is a freely available online service for fully-fledged conjugation of Portuguese
verbs. It was developed and is mantained by the
NLX-Natural Language and Speech Group at the
University of Lisbon,
Department of Informatics.
You may be also interested to use our
LX-Suite online service for the shallow processing of Portuguese.
LX-Conjugator takes a Portuguese infinitive verb form and delivers the
corresponding conjugated forms.
At the date of its inception (May 2005), it is the first freely available online service
for fully-fledged Portuguese verb conjugation, including the full range of pronominal
conjugation forms. It thus handles:
- Pronominal conjugation
The Portuguese verbal inflection system is a most complex part of the Portuguese
morphology, and of the Portuguese language, given the high number of
conjugated forms for each verb (ca. 70 forms in non pronominal conjugation), the number of productive
inflection rules involved and the number of non regular forms and exceptions
to such rules.
This complexity is further increased when the so-called pronominal conjugation
is taken into account.
The Portuguese language has verbal clitics, which according to some
authors are to be analyzed as integrating the inflectional suffix system:
With LX-Conjugator, pronominal conjugation is exhaustively handled. It is
however optional, and verbs can be
conjugated also in non pronominal conjugation mode only.
- the forms of the clitics may depend on the Number (Singular vs. Plural),
the Person (First, Second, Third or Second courtesy), the Gender (Masculine vs. Feminine), the
grammatical function which they are in correspondence with (Subject, Direct
object or Indirect object), and the anaphoric properties (Pronominal vs.
to three clitics (e.g. deu-se-lho / gave-One-ToHim_It) may be
associated with a verb form;
- clitics may occur in so called enclisis, i.e. as a final part of the verb form (e.g. deu-o / gave-It), or in mesoclisis,
i.e. as a medial part of the verb form (e.g. dá-lo-ia / give-it-CONDITIONAL).
When the verb form occurs in certain syntactic or semantic contexts (e.g in
the scope of negation), the clitics appear in proclisis, i.e. before the verb
form (ex.: não o deu / NOT it gave);
- clitics follow specific
rules for their concatenation.
Additionally, LX-Conjugator exhaustively handles a set of inflection cases
which tend not to be supported together in verbal conjugators:
- Compound tenses
- Double forms for past participles (regular and irregular)
- Past participle forms inflected for number and gender
(with transitive and unaccusative verbs)
- Negative imperative forms
- Courtesy forms for second person
LX-Conjugator handles both known verbs and unknown verbs. It thus conjugates:
- Neologisms (with orthographic infinitival suffix)
It is also worth noting the following design principles, that LX-Conjugator adopts with
respect to the so called defective verbs:
Some unsubstantiated assumptions from traditional grammar were not followed, according to which many verb forms
do not exist and/or should not be used because they sound awkward or because their use is semantically very
Accordingly, to give an example, all conjugated forms of weather verbs are
delivered, as they
can be used at least non literally (with forms other than third person
singular ones being presented in a distinguished font to indicate that they have generally
been considered non-existent). To give another example, verbs like falir
are also fully conjugated (again with some
of its forms marked in a disitinguished font in order to signal that some speakers may find them
- Special cases
LX-Conjugator does assume that some forms are impossible though (e.g. the imperative forms of verbs
such as querer / to want: *quer tu) and that some clitics do not combine with certain verb forms
(e.g. second person non-courtesy clitics and second person courtesy verb forms with the same number: *você ama-te/you_COURTESY love-yourself_NONCOURTESY).
In these cases such forms will not be produced.
Other special cases, also not generated, include impersonal se and passive se, which do
not occur with first or second person verb forms.
LX-Conjugator handles the very few cases where there may be different forms in different variants:
- Orthographic and paradigmatic differences
When the same form has different orthographic representations, all such representations are presented.
To give a couple of examples, both representations of '(he) dicharges', desagua (European) and deságua (Brazilian), and both representations for '(I) argued', argui (European) and argüi (Brazilian), are delivered.
- Other cases
Differences in irregular forms are also handled under the same approach. One such example is the past participle of 'to accept', with aceite (European) and aceito (Brazilian), which will be both displayed.
Note that in general LX-Conjugator acknowledges differences in representations of the same verb form when such representations can be predicted from the representation of the infinitive form (to be entered by the user). Accordingly, representations of the same verb differing in (the non-final part of) their roots are not automatically acknowledged by the conjugator. For instance, all conjugated forms of 'to act' will start either with act- or with at-, depending on whether the user enters actuar (European) or atuar (Brazilian) as the representation of the infinitive.
Aiming at optimizing readability and informativeness of the conjugation tables, LX-Conjugator adopts the following scheme concerning the displaying of clitics:
- Clitic placement
Variants of Portuguese may differ with respect to the relative order between the clitic forms and the verb forms. In some variants, e.g.
Brazilian, as a rule clitics occur invariably to the left of the verb form (in so called proclisis), while in some others, e.g. European, the clitics appear to the left, to the right (enclisis) of the verb, or still in medial position (mesoclisis), depending on the context where the verb form occurs. In order to preserve usability of verbal conjugators and avoid cluttering the conjugation tables with every logical possibility, pronominal forms are better generated according to one of the variants. Given that the clitic placement follows a simple rule in Brazilian Portuguese (proclisis), displaying the European Portuguese clitic placement optimizes the information provided to users. This is also the option followed by LX-Conjugator.
In European Portuguese, enclisis (and mesoclisis for Futuro and Conditional tenses) is the default clitic placement. Proclisis, in turn, is triggered by specific syntactic and semantic factors in the context where the verb form occurs. Accordingly, in the conjugation tables generated by LX-Conjugator, clitics appear in enclisis (or mesoclisis) in all tenses except those that are known to occur exactly in the contexts where proclisis is triggered (in the Conjuntivo mood: the Pretérito Perfeito, Futuro Simples and Futuro Composto tenses; in the Imperative mood: the Negativo tense). With the latter, clitics appear in proclisis in the conjugation tables.
LX-Conjugator is being developed by
António Branco and
Francisco Costa, with the help of Tiago Henriques and Filipe Nunes, at the
NLX-Natural Language and Speech Group, of the
University of Lisbon,
Department of Informatics.
The work leading to the LX-Conjugator was partly supported by FCT-Fundação
para a Cência e Tecnologia under the grant POSI/PLP/47058/2002 for the project TagShare.
Costa, Francisco, 2004, Verbal Conjugation in Portuguese, Internal report, University of Lisbon,
Department of Informatics.
Branco, António and Tiago Henriques, 2003,
"Aspects of Verbal Inflection and Lemmatization: Generalizations and Algorithms".
In Amália Mendes and Tiago Freitas (eds.), Proceedings of XVIII Annual Meeting
of the Portuguese Association of Linguistics, Lisbon, pp.201-210.
Contact us using the following email address: 'nlxgroup' concatenated with 'at'
concatenated with 'di.fc.ul.pt'.
LX because LX is the "code" name Lisboners like to use to refer to their