Characteristics of Thai Agrammatic speech

ABSTRACT

Background

Agrammatic speech is characterized by reduced speech rate, reduced utterance length and lack of grammatical complexity, with grammatical morphemes often omitted or substituted. At the word level, verbs have been argued to be particularly vulnerable: agrammatic speakers produce fewer verbs or use a less diverse range of verbs than unimpaired speakers and the use of finite verbs is compromised. However, this description is based on agrammatic narrative speech from languages that express Tense, Aspect and Agreement through verb inflection. To date, a few studies have described narrative speech in a language without verb inflection (e.g., Standard Indonesian). Thai is another language that does not use verb inflection but uses constructions with serial verbs. Another typical feature of Thai, which has not been investigated in agrammatic speakers, is the use of particles to express politeness, although agrammatic speakers of Standard Indonesian have an impaired use of (different) particles but produce the passive construction (which is a way to express politeness) to a normal extent.

Aim

The current study aimed to characterize Thai agrammatic speech and to analyse the use of verbs and polite particles.

Methods

Nine Thai agrammatic and nine non-brain-damaged (NBD) speakers participated in the study. Narrative speech was elicited in a semi-standardized interview and by picture description. First, the presence of general features of agrammatic speech were investigated in Thai: reduced speech rate and utterance length, and lack of grammatical complexity. This was followed by an in-depth analysis of verb and particle production.

Results

As in other languages, Thai agrammatic speakers talked slowly and with short utterances. However, the use of embedded sentences was normal. They produced fewer verbs, more specifically, their production of the serial verb construction was seriously impaired. Remarkably, the use of polite particles was spared, in fact, the agrammatic speakers produced more of these particles than the NBD speakers, although this may have been influenced by the context.

Conclusions

Thai agrammatic speech resembles that of other languages in terms of speech rate and utterance length. Interestingly, the specific features of Thai that were investigated, serial verbs and polite particles, both showed different patterns to normal, and merit further investigation in the future.

KEYWORDS:

• Agrammatism
• spontaneous speech
• Thai
• serial verbs
• particles

Acknowledgments

We would like to thank all of the participants who participated in this study. Our sincere gratitude goes to Assistant Professor Kalyanee Makarabhirom for her friendly assistance with data collection at the Department of Communication Sciences and Disorders, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Thailand.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1. This excludes loan words.

2. The picture illustrates children playing in a field, and adults doing agricultural work.

3. Note that all utterances that contained more than one verb were serial verb constructions.

4. Since the total number of verbs is different between the groups, calculation of the Type Token Ratio is not justified, unlike our practice in other studies (see, e.g., Abuom & Bastiaanse, 2012; Bastiaanse & Jonkers, 1998).

5. Recall that Thai is a pro-drop language; in this case, the personal subject pronoun chan: “I” was dropped, which is entirely acceptable.

Additional information

Funding

This research was supported by a grant from the University of Groningen, an Australian Government International Research Training Program Scholarship from Macquarie University (iMQRTP) to Wilasinee Siriboonpipattana and an Australian Research Council Discovery Project Grant [DP190101490] to Lyndsey Nickels. Roelien Bastiaanse is partially supported by the Сenter for Language and Brain NRU Higher School of Economics, RF, ag. № 14.641.31.0004;Australian Research Council Discovery Project Grant [DP190101490];RF Government grant from Сenter for Language and Brain NRU Higher School of Economics [14.641.31.0004];