Can we try to distinguish between actual rules and common usage?

Question

I have found that recently many answers and comments have been written in a tone suggesting that their answer is an actual grammatical or linguistic rule of English, i.e. something that must or should happen, when in reality it is simply a matter of common usage, i.e. what tends to happen, most of the time.

Examples

• The cases of usage in this answer (link accessible to who sees deleted posts)

• The percentages in this answer and its comments

Don't get me wrong. It is absolutely important to talk about common usage and how words and phrases and grammatical forms tend to be used in everyday conversation. I would even argue that this is just as important for an English language learner as understanding the technical bits of the grammar.

However, with that said, I think it is important that when something is a common usage, not a rule, that is made clear. An ELL likely would not know the difference without it being specified (that's why they're here, to learn the rules they don't know), and this can be confusing and discouraging, especially if they encounter a discrepancy in conversation soon after.

Can we please make an effort as a community to specify when something is a rule and when it is simply common usage?

Answer 1

This is an absolutely vital point, with which I am in wholehearted agreement.

I would express it a bit differently however. It's not a matter of rule versus usage, for usage is the source of rules. What's important is to distinguish:

• Practices which are always followed–rules
• Practices which are followed in specific contexts or registers–also rules, but only in those contexts or registers
• Practices which aren't rules at all, just recommendations (although they are often presented as rules by 'authoritative' sources)
• Practices which are in ‘free variation’ with alternatives, where the speaker or writer may choose whichever suits her rhythm or style

Learners need rules. They are hungry for rules which will give them clear and unambiguous guidance. Wherever we can, we should make an effort to provide them rules. But we must be very careful not to present as a rule what is merely a recommendation or a statistical trend.

I think your two examples demonstrate the difference. Bill Franke's answer is admirable: informative and helpful, but so carefully hedged and qualified that no one could mistake it for a rule. The source from which Mistu4u drew his answer (now removed), on the other hand, was illegitimate, presenting as flat rules dicta which many very accomplished writers would repudiate. However, if it had been preceded by a note making clear that it was a recommendation—“here are some ‘rules of thumb’ which may help guide your own practice”—it would be quite a passable answer. The learner gets something useful, but is not later confused when she encounters other uses.