Language production refers to how people produce language, either in written or spoken form, in a way that conveys meanings comprehensible to others. One of the most effective ways to explain the way people represent meanings using rule-governed languages is by observing and analyzing instances of speech errors. They include speech disfluencies like false starts, repetition, reformulation and constant pauses in between words or sentences; also, slips of tongue, like blendings, substitutions, exchanges (e.g. Spoonerism, an error in speech in which corresponding consonants, vowels, or morphemes are switched between two words in a phrase), and various pronunciation errors.
These speech errors yield significant implication on language production, in that they reflect that:
- Speech is planned in advance: speech errors like substitution and exchanges show that one does not plan their entire sentence before they speak. Rather, their language faculty is constantly tapped during the speech production process. This is accounted for by the limitation of the working memory. In particular, errors involving exchanges imply that one plans ahead in their sentence but only about significant ideas (e.g. the words that constitute the core meaning) and only to a certain extent of the sentence.
- Lexicon is organized semantically and phonologically: substitution and pronunciation errors show that lexicon is organized not only by its meaning, but also its form.
- Morphologically complex words are assembled: errors involving blending within a word reflect that there seems to be a rule governing the construction of words in production (and also likely in mental lexicon). In other words, speakers generate the morphologically complex words by merging morphemes rather than retrieving them as chunks.
There are three separate phases of production:
- Conceptualization: "determining what to say.
- Formulation: "translating the intention to say something into linguistic form.
- Execution: "the detailed articulatory planning and articulation itself.
The analysis of systematic errors in speech, writing and typing of language as it is produced can provide evidence of the process which has generated it. Errors of speech, in particular, grant insight into how the mind processes language production while a speaker is amid an utterance. Speech errors tend to occur in the lexical, morpheme, and phoneme encoding steps of language production, as seen by the ways errors can manifest.
The types of speech errors, and some examples, include:
- Substitutions (phoneme and lexical): replacing a sound with an unrelated sound, or a word with an antonym, and saying "verbal outfit" instead of "verbal output", or "He rode his bike tomorrow" instead of "...yesterday", respectively,
- Blends: mixing two synonyms and saying "my stummy hurts" in place of either "stomach" or "tummy",
- Exchanges (phoneme and morpheme): swapping two onset sounds or two root words, and saying "You hissed my mystery lectures" instead of "You missed my history lectures", or "They're Turking talkish" instead of "They're talking Turkish", respectively,
- Morpheme shifts: moving a function morpheme such as "-ly" or "-ed" to a different word and saying "easy enoughly" instead of "easily enough",
- Perseveration: continuing to start a word with a sound that was in the utterance previously and saying "John gave the goy a ball" instead of "John gave the boy a ball", and
- Anticipation: replacing a sound with one that is coming up later in the utterance and saying "She drank a cot cup of tea" instead of "She drank a hot cup of tea."
Speech errors will usually occur in the stages that involve lexical, morpheme, or phoneme encoding, and usually not the first step of semantic encoding. This can be credited to how a speaker is still conjuring the idea of what to say, and unless he changes his mind, cannot be mistaken in what he wanted to say.
