The explicit teaching of sentence structure - and why it’s so important

As a primary school teacher, one of the most common pieces of feedback to leave my mouth was ‘capital letters and full stops’. Be it Year 1 or Year 6, it was always the same story. I would gently prompt children whilst reading over their shoulder. I would write it in their books. I would include it on my feedback slide for the next lesson. I would use choral response — yet all year, year on year, the same mistakes were being repeated.

After much head-scratching, it dawned on me that another verse of ‘capital letters and full stops’ (and a 1, 2, 3, 4) wasn’t going to cut the mustard. It wasn’t addressing the root of the problem — it was causing it. Ask any child what makes a sentence a sentence and they’ll reply, as if taught by rote, ‘capital letters and full stops’. Although they’re not wrong, they’re not right either. This was my epiphany moment — the missing link, if you will — that children don’t actually know what the word ‘sentence’ means. It’s one used in every year of their schooling, even from the very beginnings of EYFS, but is rarely explicitly defined.

What is a sentence?

For a sentence to be grammatically correct, it must start with a capital letter and end with a full stop — that much, children know. What is often not understood is that it must also include a subject, a verb and a main clause. It can include other syntactical elements (an object, adjectives, prepositions), but a sentence is simply not a sentence without a subject, a verb and a main clause.

While some schools may explicitly teach syntax so that children have a clear understanding of sentence structure, it’s all too common for the same mistakes to appear time and time again. Here are the top three errors I have noticed within my own classroom as well as within children’s writing sent to us here at stylus.

1. Fragment sentences

Let’s start with a personal bugbear of mine that I refer to as ‘premature demarcation’ when discussing the most common mistakes spotted at KS2.

In the moonlight.

At the end of the day.

As quick as a fox.

All too often, children believe that these are sentences —  they have a capital letter and a full stop, don’t they? Teachers will recognise these examples instantaneously as fronted adverbials, written into the National Curriculum to encourage children to vary their sentence structure and add detail to their writing. What is sometimes missed by children, however, is that these phrases cannot function alone. This misunderstanding may stem from lack of exposure to some key terminology:

Phrase: a group of words that do not contain both a subject and a verb

the green door — a phrase with a subject (door) but without a verb

dancing slowly — a phrase with a verb (dancing) but without a subject

on Saturday — a phrase without a subject or a verb

To be clear, a phrase by itself is not, has never been and will never be a complete sentence. If demarcated with a capital letter and a full stop, this would be a fragment: a sentence that is not grammatically correct.

Clause: a group of words that do contain both a subject and a verb. However, this does not automatically form a complete sentence as there are two types of clauses:

Subordinate clause: cannot stand on its own as a complete sentence (sometimes referred to as a dependent clause) and includes a subordinating conjunction or relative pronoun

because he laughed — a clause with a subject (he), a verb (laughed) and a subordinating conjunction (because) that does not make sense on its own

when the rain stops — a clause with a subject (the rain), a verb (stops) and a

subordinating conjunction (when) that does not make sense on its own

If demarcated with a capital letter and a full stop, a subordinate clause would also be a fragment sentence.

Main clause: can stand on its own as a complete sentence (sometimes referred to as an independent clause or a stand-alone clause)

the dog wagged his tail — a clause with a subject (dog) and a verb (wagged) that

makes sense on its own

the doctor examined her — a clause with a subject (the doctor) and a verb

(examined) that makes sense on its own

If demarcated with a capital letter and a full stop, a main clause is not a fragment sentence: it is a complete, grammatically correct sentence. 

As already stated, a sentence must include a main clause. It can also include phrases and/or subordinate clauses, but the latter two cannot stand alone to form a sentence. With these terms explicitly defined (and, importantly, continuously revisited) debunking ‘in the moonlight’ as a sentence becomes that little bit easier. 

Frustratingly, there are further complications — isn’t the English language a wonderful thing?

A cloud of rain hovering above him.

Is there a subject? Yes - a cloud of rain.

Is there a verb? Yes - hovering.

From this, we can deduce that it’s a clause.

Is there a subordinating conjunction? No.

Is there a relative pronoun? No.

From this, we can deduce that it’s not a subordinate clause.

But is it a main clause? No. There’s still something wrong with the sentence — the tense. To use the present tense verb ‘hovering’ in this context, the auxiliary verb ‘is’ is needed to correctly construct the sentence in the progressive present tense:

A cloud of rain is hovering above him.

Alternatively, the suffix -ing could be replaced with -s to correctly construct the sentence in the simple present tense:

A cloud of rain hovers above him.

The solution:

If incomplete sentences are a running theme in your classroom, I recommend going back to the beginning: explicit teaching of grammatical terminology. Do your pupils know what a clause is? Scratch that — do they know what a verb is? The more examples (and non-examples) they are exposed to, the more likely that light bulb moment. Weave ‘is this a sentence?’ games into starters, plenaries, homework tasks — dedicate as much time as your timetable will allow. Practise, practise and, when you think they’ve got it, practise some more. 

2. Comma splicing

I can already sense the tension at the mere mention of those two words used together. It may be thought of as a contentious term, but it’s an important one to address. As teachers, we often critique children’s writing by highlighting (sometimes literally) their incorrect use of commas within sentences. For example:

I like cheese, she likes ham.

Bob ran downstairs frantically, he escaped through the garden gate.

Hobbits are usually shy, they have big feet with curly hair on the bottom of them.

In all three of these examples, two main clauses have been joined using a comma.

“I like cheese” and “she likes ham”

“Bob ran downstairs frantically” and “he escaped through the garden gate”

“Hobbits are usually shy” and “they have big feet with curly hair on the bottom of

them”

There are still some firm believers in ‘commas create a pause’ and, on that basis, all three of these sentences would be correct. But — to be blunt — that’s not what a comma is for. Sure, commas can be used to indicate a pause in some sentences. Take an embedded clause, for example:

The taxi driver, who had been on the road since 5am, grunted in response.

The use of commas in this sentence tell the reader to take a breath in order to emphasise the reason that the taxi driver was so rude. However, could the same effect be created by using other parenthetical punctuation, such as brackets or dashes? Absolutely. It’s the parenthesis that’s creating the pause — not the comma. 

We don’t pause for emphasis when commas are used within lists:

The pirate ship had three cabins, eight oars and a black flag flying at half mast.

Nor do we pause when commas are used within expanded noun phrases:

The derelict, haunted house had three broken, jagged windows.

Using a comma to join two main clauses (i.e. the comma splice) does create a pause — and this pause is warranted. However, it’s not the comma’s job to create this pause; that’s above its pay grade.

The solution:

Thankfully, there’s an easy replacement for the comma that you can teach your pupils. Three, in fact:

1. Remove the comma and separate the one incorrect sentence into two correct sentences:

I like cheese. She likes ham.

Bob ran downstairs frantically. He escaped through the garden gate.

Hobbits are usually shy. They have big feet with curly hair on the bottom of them.

2. Replace the comma with a semicolon:

I like cheese; she likes ham.

Bob ran downstairs frantically; he escaped through the garden gate.

Hobbits are usually shy; they have big feet with curly hair on the bottom of them.

3. Replace the comma with an appropriate conjunction:

I like cheese but she likes ham.

Bob ran downstairs frantically before he escaped through the garden gate.

Hobbits are usually shy and they have big feet with curly hair on the bottom of them.

As long as they have one of these three quick-fixes up their sleeve, they should be able to oust their wrongly placed comma. As for being able to identify this mistake independently, that’s where your little-but-often approach to grammatical terminology will pay its dividends — re-read step one to ascertain how to do this.

3. Run-on sentences

This final misconception is often linked with working memory; as Paul G Moss discusses in his article about cognitive load, “if grammar is not at the point of automaticity, it is neglected.” Run-on sentences tend to occur when children’s working memory is taken up by other writing components (handwriting, spelling, ideas) which, in turn, means that they do not have the mental capacity to use punctuation to indicate where one sentence ends and the next one begins. Often, the syntax of these run-on sentences are correct — they contain subjects and verbs, they communicate complete thoughts and the chosen tense is correctly constructed. The issue here lies completely within the punctuation.

the man travelled to the moon when he was there he could see the earth and all the

other planets it was incredible

How many sentences can you count in the above example? If we take ‘sentence’ to mean ‘capital letters and full stops’, the answer is zero. However, as we’ve discussed — at some length — sentences are a little more complex than that. If we demarcate this one run-on sentence correctly, we are left with three complete sentences:

The man travelled to the moon. (1) When he was there, he could see the Earth and

all the other planets. (2) It was incredible. (3)

The solution:

In my professional opinion, run-on sentences are the easiest of these errors to fix. As long as they’ve understood the different components of the sentence, they’re half way there; their next step is to then understand (or remember) how to separate these. And guess what? They can already tell you they need capital letters and full stops.

You could try walkie-talkie sentences (walking around the classroom whilst reading the sentence and stopping where there should be a stop mark); using a different coloured pen for punctuation (with the idea that this focuses children’s thinking and prompts them to use demarcation); sentence diagramming (a visual aid to demonstrate how different elements of speech relate to each other); or, if all else fails, turn to the handy highlighter (ask your pupils to highlight each type of clause they can find in alternating colours in order to find where punctuation is missing).

What’s the most important problem to fix?

Of course punctuation has its value, but a firm grasp on sentence structure and syntax is the key ingredient to writing. Without this understanding in place — without the ability to write a complete, grammatically correct sentence — how can we expect the children that we teach to become great writers? How can we expect them to be able to delve deeper and intentionally use fragment sentences for effect? How can we expect to ignite the flame that spurs them on to continue writing outside of the classroom? It’s a big responsibility being a teacher: moulding the next generation of F. Scott Fitzgeralds and Virginia Woolfs. But, before you can nosedive into figurative language and characterisation, it must all start by asking your pupils the all-important question: what makes a sentence a sentence?  With a firm grammatical foundation in place, the real fun can then begin.