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'Is that always true? - Yes it is!'

In a recent post I talked about students wanting to know whether rules are always true. As I mentioned, most of the rules I teach are guidelines about how language is typically used and not mathematical formulas (or formulae!) that work 100% of the time.

Here are some examples of rules and guidelines that are not always true.

  1. Use the past simple with past time words and phrases such as 'yesterday' and 'last week'.

  2. Go back a tense in reported speech.

  3. Past habit would is often contracted.

  4. The word treacherous means dangerous.

When I’m teaching these types of rules, I’m careful to use words such as ‘typically’, ‘often’, ‘tend’ or ‘usually’.

Rules that are always true

There are, however, times when I happily use the word ‘always’ when teaching grammar rules. These rules typically relate to how language is formed rather than used.

Here are some examples of 'always rules':

  1. The present perfect is formed using the auxiliary verb have + past participle.

  2. If modal verbs are followed by a verb, the verb takes the bare infinitive form.

  3. The pronoun I is written as a capital letter.

These rules reflect standard English and whilst it is true that they can be broken, if students did this in an exam, they could lose some marks. That's why I'm happy to use the word always when teaching these rules.

Why is it important to know the scope of rules?

Some students wrongly assume that the rules they learn apply 100% of the time. This can mean that they apply those rules too strictly or misinterpret them. One way to reduce the risk of this happening is for teachers to be clear about the scope of rules and tips that they teach.

It’s also a good idea for students to re-phrase the rule they have just learned and to ask questions about any assumptions they are making.

  • 'Is this rule always true?'

  • ‘Are there any other words that act like this?’

In fact, I was asked an excellent question by one of my students very recently. Whilst teaching linking words although, however and despite, I explained that despite can be followed by an ‘ing verb. One student asked if this meant that ‘however’ is never followed by an ‘ing verb.

This was a question that I haven’t been asked before and illustrative of the assumptions that learners may make. Coming up with such questions is a great learning strategy allowing the student and teacher to do some research to test out the idea.

In answer to this question, a quick look at Skell revealed that ‘however’ can be followed by an ‘ing verb. It doesn’t happen very often but it is possible.

Any other tips?

Yes, rules that are always true need to be carefully considered and formulated.

Let’s look at this example.

The auxiliary verb ‘do’

A. Is always followed by the infinitive

B. Is sometimes followed by the infinitive

C. Is usually followed by the infinitive

This is a bit of a trick question. In lessons I probably say option A, that auxiliary do is always followed by the infinitive but this isn’t completely true. Can you think why?

If not, read further.

Ask any kid who has been in an argument and they will tell you that did and didn’t can be used on their own, as in the following exchange.

‘You ate my cake.’




Here’s my rule for auxiliary do which works I think !!

When auxiliary do is followed by a verb, that verb always takes the infinitive form.

And here’s a simpler version for students to memorise easily.

Do/does/did + infinitive

Why use rules if they are not always true?

The simple answer is that students like having rules to follow. As long as the rules are clearly formulated and students understand that most rules are guidelines, things should be ok.

Actually students might be happy to know that some rules can be broken!

What do you think? Are you clear about the scope of grammar rules?


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