The organization of verb meaning in Lengua de Señas Nicaragüense (LSN): Sequential or simultaneous structures?

Abstract

One structural dimension that varies across languages is the simultaneous or sequential expression of meaning. Complex predicates can layer meanings together simultaneously in a single-verb predicate (SVP) or distribute them sequentially in a multiple-verb predicate (MVP). We ask whether typological variability in this dimension might be a consequence of systematic patterns of diachronic change. We examine the distribution of markers of agency and number within the verb phrase (the predicate) in the earliest stages of a young, emerging sign language in Nicaragua, Lengua de Señas Nicaragüense (LSN), beginning with homesign systems like those from which LSN originated, and progressing through two decades of transmission to new learners. We find that: (i) LSN2 signers are more likely to produce MVPs than homesigners or LSN1 signers; (ii) in the MVPs they do produce, homesigners and LSN1 signers are more likely to produce predicates that mark both agency and number simultaneously on at least one of the verbs; LSN2 signers are just as likely to produce sequences with verbs that mark agency and number in sequentially separate verbs. We discuss how language acquisition, modality, and structure, as well as specific social factors associated with each of the groups, play a role in driving these changes, and how, over time, these patterns of change might yield the diversity of forms observed across spoken and signed languages today.

Figure 1:

A predicate structure from American Sign Language (ASL) that means two-frail-humans+move- forward+carefully+side-by-side containing five meaningful simultaneous components—’two’ is represented by the hands, ‘people’ by the two index fingers, ‘frail’ by the two bent knuckles, ‘move-forward’ by the direction of movement away from the signer, and ‘carefully’ by the pressed lips. [Reprinted with permission from Brentari, 1998].

Figure 2:

Still images drawn from classifier constructions in ASL with the following glosses in English (descriptions of the scene described follow each gloss): (a) Pen-on-horizontal-surface (scene: no-agent/single object/no movement); (b) Pens-on-horizontal-surface (scene: no-agent/multiple objects/no movement); (c) Someone-put-pen-on-horizontal-surface (scene: agent/single event/movement); (d) Someone-put-pens-on-horizontal-surface (scene: agent/multiple event/movement) [Images reprinted from Brentari et al. 2020 with permission].

Figure 3:

Single verb predicates (SVPs), repeated to express plurality, illustrating: (a) redundant marking for agent on the handshape (handlingHS) and movement axis (midsagittal); (b) agent marking on handshape only (handlingHS); (c) agent marking on the movement axis only (midsagittal).

Figure 4:

Multiple-verb predicates (MVPs) illustrating: (a) a “mixed” form with partial redundancy on V1 and V2: V1: plural (repetition) and agent (handshape and axis) and V2: plural (repetition) and no-agent (handshape and axis); (b) a “split” form with no redundancy between V1 and V2: V1: agent handshape (handshape and axis) and V2: plural (repetition) and no-agent (handshape and axis).

Figure 5:

A sample single-verb predicate (SVP) and multiple-verb predicate (MVP) description from the data set for the same condition (condition 7): (a) illustrates an SVP with multiple midsagittal movements produced by a Homesigner for putting multiple pens on a table in a row; (b) illustrates an MVP produced by an LSN2 signer—V1 includes agent (handling handshape) + plural, and V2 includes no-agent (object handshape) + singular for putting multiple marbles on a table in a row. The videos of these responses, with glosses, are available in the project OSF repository.

Figure 6:

The proportion of predicates marked for agent for each of the three language groups (Homesign, LSN1, LSN2) for trials with (right) and without (left) an agent. Agent is marked by a handling handshape (HHS), midsagittal movement axis, or both (black dots). No-agent is marked by object handshape (OHS; gray triangles). Each dot represents a participant; the upper and lower bounds of the boxes indicate the first and third quartiles, and the horizontal bar in each box shows the group mean.

Figure 7:

The proportion of predicates marked for number for trials with a single object (left) or multiple objects (right). Singular is marked by one movement (no repetition, black dots); plural is marked by repetition (gray triangles). Each dot represents a participant; the upper and lower bounds of the boxes indicate the first and third quartiles, and the horizontal bar in each box shows the group mean.

Figure 8:

Predicted probabilities of a multiple-verb VP response in descriptions of scenes classified according to Agency (Agent, red circles; No-Agent, blue circles), and Number of objects (Single Object; Multiple Objects) in Homesigners, LSN1 signers, and LSN2 signers. The data set is available in the project OSF repository.

Figure 9:

The proportion of responses marking both agent and plural classified according to whether the two are: simultaneously produced on the same verb (simultaneous: V1: agent+plural (gray dots)); the two are produced simultaneously on one verb, along with either marker on a separate verb (mixed: V1:agent+plural, V2: agent: (black triangles)); or the two are produced sequentially, agent on one verb and number on another (sequential split: V1: agent, V2: plural (black squares)). Each dot represents a participant; the upper and lower bounds of the boxes indicate the first and third quartiles, and the horizontal bar in each box shows the group mean.

Figure 10:

A homesigner producing a partially redundant mixed MVP to describe an agent putting multiple planes on the table in a row (condition 7).

Figure 11:

An LSN1 signer producing an SVP to describe an agent putting multiple books on the table (condition 7).

Figure 12:

An LSN2 signer producing a split, non-redundant MVP to describe an agent putting multiple lollipops on the table in a random arrangement (condition 8).