Eckhard Bick - VISL

VFIN nominal group
3a) '-o' 1S M S
3b) '-a' 3S, 1/3S F S
3c) '-s' 2S P
3d) '-ar' 1/3S FUT SUBJ ADJ M/F S
The solution for these cases is text dependent. Many text types do not contain 1.person
verb forms, and here, VFIN could be routinely discarded. However, my parser is meant
to be able to handle any written text, so more complex disambiguation is appropriate,
involving nominal group agreement and checking for personal pronouns.
In (3c) there is a tendency towards avoiding 2.person verb forms which have
become all but non-existent in Brazilian Portuguese. (3d) is comparably rare, but
difficult to tackle. (3b), finally, is the most problematic, since both the verbal and the
nominal reading are very common. Worse, while a feminine article "a", preceding the
word form, might be a way to recognise NP-agreement, it is not in this case, since the
article itself is multi-ambiguous, one reading being that of object pronoun, which in
Portuguese is very common in front of finite verbs.
The 12% chance of confusing VFIN with INF is problematic for syntactic
reasons, too. It involves the future subjunctive readings that are often crucial for the
recognition of relative subclauses, a typical corollary error being the a wrong choice in
the pronoun-conjunction ambiguity of "se". The inverse case, INF vs. VFIN, is -
quantitatively - even worse: 75% of all infinitive readings (virtually all regular
infinitives) can also be read as finite future subjunctives.
The friendly cases are gerunds, which are both rare and morphologically well
defined by the nearly unmimickable ending '-ndo', and proper nouns, that have the
advantage of capitalisation marking, and only in sentence initial position pose certain,
limited problems. In fact, part of the disambiguation load for the PROP class resides in
the morphological analyser (tag assignment level), i.e. before the level table (2) is
concerned with (cp. section 2.2.4.4).
As could be expected, the word class internal ambiguity is highest in finite verbs,
due to the rich inflexional possibilities and stem variations.
(4) revista
"revestir" V PR 1/3S SUBJ VFIN ‘to cover’
"revistar" V IMP 2S VFIN ‘to review’
"revistar" V PR 3S IND VFIN ‘to review’
"rever" V PCP F S ‘to see again’, ‘to leak through’
"revista" N F S ‘magazine’, ‘inspection’
For nouns, the second largest group in this respect, class internal ambiguity is much
lower, since its typical inflexions (the singular '-a' and '-o', as well as the plural '-s') are
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