Shenk, C., & Cokely, D. (1991). Subjects and Objects. In American Sign Language: A Teacher's Resource Text on Grammar and Culture . Washington, D.C.: Clerc Books, Gallaudet University Press.
To express a full idea in ASL, it requires the use of subjects and objects in a way that is different from English. This requires a strong command of spatial agreement. In modifying the way a verb is expressed, making use of a particular sign order for verbs that cannot be modified, and changing the body position of the signer are all ways in which the subject and object can be expressed.
Reciprocal verbs, body-anchored verbs, non-directional verbs, and geographic location verbs are all methods of conveying the subject and the object of a statement. Reciprocal verbs require both hands doing the same actions simultaneously to indicate that the action is performed by two people, things, or groups. The hands represent the action performed, which conveys that the hands are two subjects. An example of this is two people looking at each other, and then turning to walk away, or two teams discussing something, and coming to an understanding together. Body-anchored verbs require performing the sign on the actual location of the body to which it occurs or occurred. This means that the location of the sign is always changing based on which part of the body it is describing. For example, kisses on the cheek, or scratching my arm, or a cut on my arm, my cheek, or my leg. Non-directional verbs rely on clearly stating the subject to which the verb is occurring. The verb is unable to show the direction of its influence, therefore the sign is performed as usual, and is assumed to be happening to the already indicated subject. For example, my boyfriend loves me, or Sarah dreams about school being over and going to the beach in the summer. Geographic location verbs describe the movement from one physical location to another. By indexing a starting point and an ending point, ASL then uses the sign to travel between the points to signify moving from one location to the other. Two examples would be flying from Toronto to New York City, or driving from Vancouver to Halifax.
While I understand the concept of subjects and objects, and I try to be consistent with it in my signing, I do still have some difficulty in retaining which signs are directional and non-directional. Many of them are quite obvious, but there are also a great many of them that I am not sure of how to produce. I have a similar issue with producing reciprocal verbs in that I am not always sure how to properly produce them for a number of different verbs.