AAC (Augmentative and Alternative Communication) - the field of study devoted to the use and development of speech-generating devices (SGD) and other methods of augmenting natural communication for people with communication disabilities.

Auxiliary verb - a helping verb, often located in from on the main verb, as in this example: I am writing to you.

Brown’s Stages - identified by Roger Brown and described in his classic book (Brown,1973). The stages provide a framework within which to understand and predict the path that normal expressive language development usually takes, in terms of morphology and syntax.

Communicative Competence - the ability to functionally communicate within the natural environment and to adequately meet daily communication needs. It is suggested that this is accomplished by the integration of knowledge, judgement, and skills in the area of linguistics, operational, social, and strategic competence. Source: Brookes Publishing, AAC Glossary

Contractible copula - the shortened form of the verb “to be” when it is the only verb in the sentence.

Core vocabulary - words that are frequently used. Core vocabulary is identified in empirical research or clinical reports that measure vocabulary use patterns for many individuals.

Fringe vocabulary - vocabulary specific or unique to the AAC user or to one activity or topic. (Beukelman & Mirenda, 1998)

Imperatives - verbs used to give orders, commands, or instructions, such as Listen! or Help me!

Independent communication - characterised by short or long sentences composed by the speaker. Not pre-stored sentences.

Infinitive - the “to” form of the verb, such as to go, to want, or to do.

Infinitive complement - the entire phrase that includes an infinitive. In the sentence “Don’t forget to stop at the store,” to stop is the infinitive, and to stop at the store is the infinitive complement.

Irregular Past Tense - many verbs in English form their past tense with “-ed”; some do not. These are called irregular verbs, and they include some of the most common verbs in English, such as ate, went, and did.

Interrogative - pertains to a question.

LAM (language activity monitor) - a system for recording and analysing the language output of a speech generating device (SGD).

Literacy - the state of being able to read and write.

LRM (language representation method) - refers to the three ways to represent language commonly used in AAC: spelling, single meaning pictures, and semantic compaction (Minspeak®).

MAP (Minspeak® application program) - there are several Minspeak® application programs. They run on PRC devices and are focused on independent communication. Unity® is a fifth generation MAP.

Memory load - the power or process of reproducing or recalling what has been learned and retained, especially through associative mechanisms.

Metaphor - a figure of speech in which a word or phrase literally denoting one kind of object or idea is used in place of another to suggest a likeness or analogy between them. Example: drowning in money.

Minspeak - combining sequenced multi-meaning icons to represent a private code between a user and his/her computer system.

MLU-m (mean length of utterance - morpheme) - Children go through many stages that are characterised by different utterance lengths. Children aged 18 to 27 months characteristically have utterances of 1.75 words. A rule of thumb is MLU-m equals age until 5. Successful augmented communicators have MLU-ms of 9.

Modals - verbs used to express ideas such as possibility, intention, obligation and necessity, such as could, should, and would.

Morpheme - the smallest unit in the grammar that is either a word in its own right (free morpheme) – cook – or part of a word (bound morpheme “-s”) – cooks. Source:

Morphology - the study of word structure.

Morphological Structure - the scientific study of the structure & form of words and phrases.

Multi-meaning pictures - pictures that are systematically used to mean more than one thing through some process of disambiguating the meanings of the pictures when used with an AAC device or system.

Motor planning - the execution of a motor movement with precision and automaticity.

Navigation - the process of moving through pages or rows of vocabulary on an AAC device.

Non-picture producers - words which cannot be represented with pictures that can be interpreted across languages and cultures without explanation or training.

Object - the receiver of the action in a sentence.

Pages - a form of vocabulary organisation that uses configurations of grids, like pages, and arranged in either paper or electronic formats as if they were pages in a book.

Picture producers - words that can be represented with pictures that can be interpreted across languages and cultures without explanation or training.

Plural - a word that expresses more than one.

Possessive - in grammar, a possessive word showing to whom or what something belongs.

Pragmatics - language development skills in the context and environment that include such factors as strategies for topic setting, strategies for clarification and repair, and strategies for decision making about when to use which communication modality. Pragmatic consideration enables more effective communication interactions. Source: Brookes Publishing, AAC Glossary

Present progressive - word tense in which conditions are happening all the time, gradually.

Script - a predetermined stereotyped sequence of actions that defines a well-known situation (Schank and Abelson, 1977) Source:

Secondary iconicity - the lesser meaning(s) of any picture or visual representation.

Semantic compaction - the systematic exploitation of secondary iconicity to provide large vocabularies within a small iconic space.

SGD (speech generating device) - this abbreviation is replacing VOCA (voice output communication aid) as an abbreviation for an electronic augmentative communication device.

Single-meaning pictures - pictures that are intended to mean only one thing when used with an AAC device or system.

SLT (speech language therapist) - refers to a person practicing speech therapy

SNUG (spontaneous novel utterance generation) - speech-generating devices are often pre-programmed into utterance level language units (full sentences). A novel utterance is a sentence a client has generated for him or herself word by word. Independent communication is generally conducted with spontaneous novel utterances.

Syntax - the grammatical arrangement of words in a sentence.

Uncontractible Copula - the full form of the verb “to be” when it is the only verb in a sentence. Examples: Are they there? Is she coming?

Unity® - a language program designed to enhance independent communication. Based on language principles Unity can address communication needs of a wide range of early learners and adults with complex communication needs.

Links to Useful On-line Glossaries

AAC Terminology

Language Terminology