Constructive structure is a grammatical aspect often used in ASL. It compares or contrasts two persons, things, or ideas. It also often functions as 'AND' as well as 'OR' in ASL sentences.
When talking about these two things, the signer establishes these referents in specific spatial locations, one on the left side and one on the right of the signer which are the two points of reference.
my father "have" [loc-left]one brother [loc-right]three sister.
In contrastive structure, the right-handed signers usually first refers to the left and then to the right, while the left-handed signers starts in the right space, using body-shifting.
When talking about two sets of siblings, it doesn't matter which brothers or sisters you start with in the left space. It can be either "# brothers and # sisters" or "# sisters and # brothers".
But, once you establish the referents in their locations, you should retain the same points of reference for these referents when you point to them.
The signer in the video clips below shows you a couple of examples: a non-contrastive structure and a contrastive structure, talking about the same topic in both of these examples.
in-past college ix[she/he] learn+ french 3 years.
The video clip above shows a non-contrastive structure. The signer talks about one thing or a general thing and its referential space is in front of the signer.
in-past college[up-brows] ix[she/he] learn+ [loc-left]french three years, [loc-right]spanish 2 years.
The signer uses the contrastive structure talking about two different things (e.g. languages) that the person was learning. She uses body shifting to refer to two languages and their length of learning.
If the signer talks further about it, she can refer to the specific space (pronominalization) using index finger pointing. For example: ix-left i remember most, ix-right i forgot all. She can point to the left space (which is French), "I remember most" and points to the right space (Spanish), "I forgot all."
The referents french, 3 years, and remember most are referred to the left space, while the others are referred to the right space.
After establishing these referents in their locations, the signer uses body-shifting, eye-gazing, and pointing -- these forms of pronominalization -- to refer to these referents. It's the same way you use pronouns in spoken language.
By using these pronouns in sign language, it isn't necessary to repeat the nouns or subjects as long as the signer maintains the same points of reference as she talks about them until the subjects change. Spatial references are usually temporary.
Also see listing and ranking grammar when talking about three or more referents.
See role shifting (body and gaze shifting) for another related grammatical structure.