Welcome to Oxford Online English!

In this lesson, you can learn the most important grammar rule in English.

Of course, you need to know many things to use grammar correctly in English.

However, there's one tip that can dramatically improve your English grammar—especially

in writing.

First, don't forget to check out our website: Oxford Online English dot com.

We have many free lessons to help you improve your English.

There's also a level test, which can show you how good your grammar is now.

But, you want to hear the grammar tip, right?

What is it?

Let's see!

Here's the basic idea: make sure your sentence has a subject and a verb, and that you know

what the subject and main verb are.

Every sentence needs a verb, and unless your sentence is an imperative—meaning that you're

giving someone a command—then your sentence needs a subject, too.

Each clause in your sentence should have one subject and one main verb, and only one subject

and one main verb.

It sounds simple.

Maybe you're thinking, 'This is too easy!

I know this already!'

However, we see students make mistakes with this all the time, especially in writing.

Mistakes with this point are serious, because they often make it hard to understand what

you want to say.

Even if your meaning is clear, sentences with this problem are often difficult to read.

In any situation, that's a problem.

It's especially serious if you're taking an exam, like IELTS.

Let's look at the most basic point.

Your sentence needs a subject, which should be a noun or noun phrase, like 'they',

'everybody', or 'my maths teacher from high school'.

Then, you need a main verb, which generally goes after the subject.

With this, you can make simple sentences like these: 'They have a nice house';

'Everybody agreed.'

'My maths teacher from high school was really good at explaining complicated things.'

After the main verb, you might have a simple complement, like 'a nice house'.

You might have nothing at all.

Your sentence might finish after the verb, like 'Everybody agreed.'

Or, you might have a longer complement, possibly including other verbs, as in 'My math teacher

from high school was really good at explaining complicated things.'

So, you're probably still thinking that this is easy.

And, so far, it is!

Let's see how it can go wrong.

Look at five sentences: By the way, these sentences are all real examples

from our students' writing.

Most of them come from IELTS writing practice.

All these sentences break the basic rule we mentioned above.

Can you see how?

Pause the video, read the sentences, and try to find the problems.

Start again when you're ready.

In the first sentence, there's no main verb.

'Will' is a modal verb, but a modal verb can't be a main verb; you need a main verb after

it.

For example, 'We will *go* back home next Friday.'

The second sentence has two subjects: 'Imposing higher taxes on fast food' and 'it'.

One clause can't have two subjects.

To correct this sentence, remove 'it': 'Imposing higher taxes on fast food *is*

a good idea.'

The third sentence has a main verb, but no subject.

*What* affects individuals' lives directly?

This is difficult to correct, because it's impossible to know what the writer wanted

to say.

You would need to add a noun before the verb 'affects' to make it understandable.

The fourth sentence has a fragment at the end which includes a subject and a verb.

This means the sentence has too many subjects and verbs; each clause can only have one subject

and one main verb.

What's the solution?

There are many possibilities, but the easiest way to correct this is to break the sentence

into two parts.

You can do this by changing the comma after 'Alexandria' to a semicolon.

Finally, what about the fifth sentence?

It's difficult to understand, right?

Again, it's difficult to correct this sentence, because it's hard to see the writer's

ideas.

The problem is that this sentence has several parts with several subjects and verbs, and

it's not clear what refers to what.

For example, 'each society' is a subject, but then 'forced medical treatment' is

also a subject.

Later in the sentence, we have a verb—'avoid'—and it isn't clear which subject goes with it.

On a more practical level, it just isn't clear what this sentence is about.

Does the writer want to say something about 'each society', or about 'large sets

of people,' or about 'forced medical treatment'?

We don't know.

This is why subject-verb structure is so important: if it isn't clear, it will be hard to understand

what your sentence is about.

Sometimes, this might mean that your ideas aren't clear in your mind.

Next, let's expand this basic rule and see how you can use it to make a wider range of

sentences.

You heard before that both subjects and verbs can be words or phrases.

Sometimes, your subject or verb might be a longer phrase.

This often leads to mistakes, because when your subject and verb are multiple words,

it's more difficult to keep track of your sentence structure.

Let's do an example together.

Take a sentence you saw before: 'Everybody agreed.'

You can make the subject—'everybody'—into a phrase.

For example: 'Everybody who was at the meeting agreed.'

You can make the verb into a phrase, like this: 'Everybody who was at the meeting

agreed to change the office dress code.'

You can make each phrase even longer.

For example: 'Everybody who was at the board meeting held last Tuesday evening agreed to

change the existing office dress code to something more informal.'

Even though we've added lots of new words and ideas, this sentence has the same basic

structure as before.

It still has one subject, and one main verb.

Although we've added a complement after the verb, the verb doesn't have a direct

object.

We haven't added anything grammatically new to the sentence; we've simply expanded

the existing parts.

Let's do one more example of this.

This time, we want you to try!

Here's a basic sentence: 'My sister called.'

Can you make this sentence longer by changing the subject and verb to longer phrases?

For this exercise, there are a couple of rules.

You can't add a noun after 'called', because that would change the structure.

You also can't use conjunctions like 'although' or 'because'.

The idea is to keep the basic structure the same, so that the sentence has one subject

and one verb which doesn't have a direct object.

Pause the video and try it now.

How did you do?

Of course, there are many ways to do this.

Let's look at three possibilities.

'My sister Mandy called last night.'

'My sister, who I haven't spoken to for ages, called to tell me about her new job.'

You can see that you can do this in a simpler way, or you can make the sentence much more

complicated, by adding relative clauses, adjectives, adverbs, and so on.

However, remember the basic idea: all of these sentences have the same basic structure: one

subject and one main verb.

Let's move on and talk about one more important point.

As you heard before, almost all sentences need a subject.

Only imperatives, like 'Come here!' don't need a subject.

Interjections, like 'Wow!', also don't need a subject, but many linguists—including

us—would say that these are not sentences.

However, sometimes there isn't a clear noun subject.

In this case, you need to use a word like 'it' or 'there'.

For example: 'It won't take long to get there.'

'It's worth going.'

'There's a mosquito on your nose.'

'There have been several developments since the last time we spoke.'

In these sentences, the words 'it' and 'there' are empty subjects; they don't

refer to a specific noun or thing.

You use them only because the sentence needs a subject.

They don't add any meaning to the sentence.

So, what's the difference?

When do you need to use 'it', and when do you need to use 'there'?

Use 'it' to talk about distances and times.

For example: 'It's not far to the metro.'

'How long will it take you to finish everything?'

'It's six thirty.'

You often use 'it' to talk about the weather, too.

For example: 'It's sunny.'

'It'll be cold tomorrow.'

'It was really wet last month.'

You also use 'it' to talk about situations, and in a number of phrases like 'it's

worth…'

For example: 'It's safe to walk around at night here.'

'It's good that you could join us.'

'It's really cosy in here.'

What about 'there'?

Use 'there' to say that something exists, or doesn't exist.

Usually, when you use 'there', it's the first time you're mentioning something.

For example: 'There's some salad in the fridge.'

'There are several reasons why I have to say 'no' to this idea.'

'There didn't use to be so many homeless people here.'

Let's practise together.

Look at five sentences.

Do you need to add 'it' or 'there'?

Pause the video, and think about your answers.

Ready?

Here they are.

Finally, we have one more thing to show you.

In general, the subject of your sentence goes immediately before the main verb.

You can see this in the sentences you've already seen in this lesson.

Sometimes, the main verb also has an auxiliary verb, like 'have', 'has', 'do',

'does', 'will', 'can' and so on.

In positive sentences, the auxiliary verb and the main verb almost always go together.

For example: 'They have bought a nice house.'

'My sister Mandy will call tonight.'

However, there's one case where the main verb goes before the subject: questions with

'be'.

For example: 'Are you ready?'; 'Were there many people there?';

In some cases, the auxiliary verb needs to come before the subject.

This is most common in questions.

For example: 'Can you help me?'

'What time does she arrive?'

'How many pieces of cake have you had already?'

It's also possible in certain structures which are mostly used in formal writing, like

'At no time did I suspect that he was the thief.'

At this point, let's review the most important points that you should take away from this

lesson.

One: make sure every sentence has a subject and a main verb in each clause.

Don't put more than one subject or main verb in one clause.

Two: if your subject and main verb are longer phrases, or if you add a lot of adverbs or

subordinate clauses to your sentence, it might be harder to keep track of the structure.

Before you write a sentence, think about this question: what are you talking about, and

what are you saying about this thing?

Decide what you're talking about—the subject—and what you're saying about it—the main verb.

Keep these in your head.

Three: study the difference between main verbs and auxiliary verbs.

Remember that auxiliary verbs can't generally be used alone.

Make sure every auxiliary verb has a main verb attached.

Learn the cases when the auxiliary verb needs to come before the subject.

If you can follow these simple steps, your writing will be clearer, better-organised,

and more accurate.

Do you have any tips to help other English learners improve their grammar?

Please share your suggestions in the comments!

Thanks for watching!

See you next time!