Teachers often tell pupils to use a ‘full sentence’ in their answers, but what is a full sentence?

Parts of a Sentence

First of all, it’s important to know what all the words in the picture mean. (Note that the parts of a sentence are not always individual words, though they can be. For example, ‘she’ is the subject, but ‘a hot dog’ is the direct object even though it is three words.)

Subject

The subject of the sentence performs the action of the verb, in other words, “who’s doing the doing”. The girl in the picture is obviously the one doing the eating, not the hot dog!

Verb

The verb is often called the ‘doing word’, although some verbs like ‘being’ and ‘having’ don’t really involve much ‘doing’! Again, what’s being done is obviously shown by the word ‘ate’. There are two kinds of verb:

• Transitive verbs need a direct object, like the word ‘ate’ in the picture
• Intransitive verbs don’t need an object, like the word ‘swim’ in ‘They swim’.

Object

There are two kinds of object:

• Direct objects are directly affected because they ‘suffer the action of the verb’. In other words, they have something done to them, like the hot dog in the picture.
• Indirect objects are only indirectly affected, for example if they benefit from the verb like the teacher receiving an apple in the picture below.

Types of Sentence

Now we know what the parts of a sentence are, we can talk about all the possible kinds of full sentence.

1. Verb only
   Strictly speaking, all you really need to make a full sentence is a verb. For example, ‘Sit!’ is a full sentence, even though it only has one word in it. That only works when you’re telling a dog – or a person! – what to do. Most of the time, you need a subject as well.
2. Subject-Verb
   ‘He swims’ is a full sentence because it has a subject and a verb, but this only works because the verb is intransitive, which means it doesn’t need an object.
3. Subject-Verb-Object
   The picture above shows the main parts of a simple sentence, which are the subject (S), the verb (V) and the object (O). The initial letters give us a typical pattern for a sentence, which is SVO. In this case, the object is a direct object, which means it’s directly affected but it can also be an indirect object, which may benefit indirectly. Here, the hot dog is the one that has to suffer being eaten – not the girl! – but it’s slightly different in the next picture. 
4. Subject-Verb-Indirect Object-Direct Object (or Subject-Verb-Direct Object-Indirect Object)
   Here, the apple is being ‘given’, so the apple is the direct object, but the teacher also benefits indirectly, so she is the indirect object.

Common Mistakes

1. Punctuation
   Every sentence should end with either a full-stop, a question mark or an exclamation mark, but one common mistake is to put a comma in between sentences instead, eg He loved pizza, he always chose pepperoni. This is called the ‘comma splice’.
2. Fragments
   A sentence that doesn’t have a subject, verb or object when it needs one is called a ‘sentence fragment’, eg Gave his teacher an apple. It’s obvious that it doesn’t make sense without the word ‘He’, but it’s easily done.
3. Starting with conjunctions
   Teachers often tell their pupils not to start a sentence with ‘because’. When asked a question like ‘Why is Jack sad?‘, it’s easy to write ‘Because his dog died‘. That’s all right when you’re speaking in class – when people don’t care as much about their grammar – but not when you’re doing your homework. It’s not always wrong to do it, though. If you use ‘because’ to link two sentences together, that’s fine, eg Because it was so sunny, I had to wear sun cream.

If you think you’re ready, here are a few sample questions. Which of these is a full sentence?

1. Because I’m cold.
2. From front to back.
3. Ran down the road.
4. The girl brushed.
5. He always did.
6. Yes.
7. Hello.
8. Why is the sky blue?
9. Shut the door!
10. He tapped.