  Abugida refers to a phonogram writing system where each syllable is
represented using a single consonant or typographic ligature, along with a
default vowel or optional diacritic(s) to denote other vowels. However, texting
in these languages has some unique challenges in spite of the advent of devices
with soft keyboard supporting custom key layouts. The number of characters in
these languages is large enough to require characters to be spread over
multiple views in the layout. Having to switch between views many times to type
a single word hinders the natural thought process. This prevents popular usage
of native keyboard layouts. On the other hand, supporting romanized scripts
(native words transcribed using Latin characters) with language model based
suggestions is also set back by the lack of uniform romanization rules.
  To this end, we propose a disambiguation algorithm and showcase its
usefulness in two novel mutually non-exclusive input methods for languages
natively using the abugida writing system: (a) disambiguation of ambiguous
input for abugida scripts, and (b) disambiguation of word variants in romanized
scripts. We benchmark these approaches using public datasets, and show an
improvement in typing speed by 19.49%, 25.13%, and 14.89%, in Hindi, Bengali,
and Thai, respectively, using Ambiguous Input, owing to the human ease of
locating keys combined with the efficiency of our inference method. Our Word
Variant Disambiguation (WDA) maps valid variants of romanized words, previously
treated as Out-of-Vocab, to a vocabulary of 100k words with high accuracy,
leading to an increase in Error Correction F1 score by 10.03% and Next Word
Prediction (NWP) by 62.50% on average.
