Learn English – the difference between “grammar” and “usage”

differences

I'm surprised this has not been asked and answered on this Site–perhaps it has, but my search found nothing. The closest question to this one i could find sought the difference between grammar and syntax, which received one answer before it was closed as off-topic. In any event, I did not find the answer probative of the question i ask here.

What's more, Internet search engines were no help, likely because there's no distinctive keyword in the query.

Best Answer

I too have searched for a definitive answer to this question and not found one. My own way of differentiating grammar from usage errors for my English language learners is as follows:

  • If the mistake contravenes a generalizable rule for all members of that word class, then it is a grammar mistake. Otherwise it is a usage mistake.

For example:

He live in Frankfurt contravenes the rule that verbs in the 3rd person singular present simple tense require an -s (with the exception of modals), and is hence a grammar mistake.

My grandfather is a very high man is a usage mistake. We can formulate a rule that high applies to mountains not people. But the rule applies to one member of the word class only and hence the mistake is one of usage.

On this basis, these errors are grammar errors:

  • I play tennis yesterday.
  • Do you have dog?
  • I live in Frankfurt since 10 year. (3 errors)

And these are usage errors:

  • I always enjoy to sleep late on Sundays.
  • What is the reason of your lateness?
  • She replied she didn't know the answer.

The issue is of more than purely theoretical importance because learners need to know whether they should consult a grammar book or a good dictionary/usage manual to find out if what they have written is correct.

It is interesting to note that two excellent resources for English language learners both have the word usage in their titles:

Garner's Modern American Usage and Swan's Practical English Usage.

Garner's book exclusively contains what I personally would define as usage issues, while Swan's includes numerous entries on what I would term grammar; including negation, passive, modals, determiners, etc. So it seems that even the experts can't agree on the meaning of the word.