A good way to begin this piece is to move from what grammar is not, to what grammar is; then to tie these clarifications to the debate on what is acceptable in verbal communication. First things first, grammar is not the ability to use sophisticated or high-sounding words in order to prove difficult to be understood. That is called grandiloquence, not grammar.
To set the record straight, grammar has two major meanings. First, it is the natural ability to speak one’s mother tongue – the spontaneous use of an indigenous language. Second, grammar means the rules that guide a language.
In line with the latter definition, a sentence that is well-formed is adjudged to be grammatical, and a sentence that does not conform to the rules is considered ungrammatical. This second definition is the core of this piece. This is because knowing a language is knowing its grammar, and knowing the grammar of a language is knowing the language.
While grammaticality is dependent on competence in a language, acceptability is sociologically based (Lamidi; 2008). This implies that grammaticality and acceptability are on two different terrains. For perspective, a sentence can be grammatical without being acceptable, and an acceptable sentence may not be grammatical. The rest of this piece will tease out the nexus of these two concepts.
As disclosed earlier, a sentence can be grammatical without being acceptable. One reason for the unacceptability of a sentence is when it is not informative. A good example that readily comes to mind is Noam Chomsky’s popular sentence: “Colourless green ideas sleep furiously.” While this sentence is grammatical, it is completely nonsensical; hence, unacceptable. First, “idea” is an abstract noun that cannot have a colour, yet it is said to be green. Beyond that, ideas do not sleep; and even if ideas could sleep, one wonders if anyone slept furiously.
The second way a sentence can be grammatical but unacceptable is when it is too long or too complex. Borsley (1971) gave an example which is: “The man the girl the boy knows likes is here.” Even though this sentence is grammatical, it is unacceptable given its complexity. The sentence can be broken down thus:
The boy knows the girl.
The girl likes the man.
The man is here.
With the stress of breaking it down, the sentence is not natural. An acceptable sentence, therefore, has to be natural and easily comprehensible.
One other way a sentence can be unacceptable yet grammatical is for the sentence to contradict itself. Two examples from Lamidi (2008) are as follows:
He survived the fatal accident.
They killed the man, but he did not die.
Notably, a fatal accident is one involving death; so it is nonsensical to say someone “survived” a fatal accident. Similarly, it is absurd to say someone was “killed” but did not “die”. These contradictory expressions are unacceptable in language use.
On the other side of the coin, some expressions are acceptable in natural conditions of language use even though they flout grammatical rules. Such expressions are heard even among native speakers of English, especially in spoken discourse.
Some of such utterances will be considered viz-a-viz their standard variants. Commonest among them is the use of the objective personal pronouns after linking verbs such as “am”, “is” and “was”. While it sounds more natural and, thus, acceptable to say “It was me” when replying to a statement such as “Who did it?”, it must be mentioned that the grammatical sentence should be “It was I.”
This is because when realised in full, the expression would read as: “It was I (not me) who did it.” Also, reporting popular Nigerian usage, it is commoner and has almost become more natural to say “between you and I” even though the standard expression is “between you and me”. This is because personal pronouns occuring after prepositions should be in the objective form.
Also prominent in prescriptive grammar are the rules that one must not start a sentence with a conjunction and end a sentence with a preposition. At the level of communication, however, one finds that the conjunction “and” has a significant discourse value in a sentence such as: “And the match started!”
Equally, saying, “He was the man I spoke to” sounds more natural than saying, “He was the man I engaged in an interaction.” The proscription of a preposition in the final position of a sentence is, therefore, a rule that is devoid of naturalness.
How, then, do we balance these two ends? Grammaticality and acceptability are two important sides of the same coin. Anyone who hopes to speak a language with finesse must understand the basic grammatical rules of such a language. However, users must also be mindful of contexts and situations to determine appropriateness during communication. This is the core of acceptability in language use.