Writing Sentences Correctly
A high-quality essay is composed of high-quality sentences. This page focuses on rules for writing complete sentences that flow together to create a well written academic piece.
Clauses and Sentences
Conjunctions and Transition words
Sentence Structure
Clauses and Sentences are the structures through which we communicate our ideas. Understanding what constitutes a clause and a sentence is important for clear writing and accurate punctuation.
Clauses are the smallest grammatical units that carry meaning. They consist of two parts: a subject and a predicate. The subject is a thing, animal or a person. The predicate tells us what the subject is doing, or what state it is in. The predicate must contain a verb that is in the finite form (a form that indicates time and does not just have ‘to’ in front of it).
Sentences must also contain a subject and a predicate, but the difference is that a sentence is always a complete idea or thought that can stand alone. A clause, on the other hand, can be a complete idea, and so equal to a sentence, or it can be part of an idea, and so not able to stand on its own without some more information.
Examples and Explanation
In the sentence ‘I went to work.’, ‘I’ is the subject and ‘went to work’ is the predicate. The verb in this sentence is ‘went’, which is the past tense of ‘to go’.
The following is another example: ‘The research on the issue was completed by a large team.’ In this example, ‘the research’ is the subject and ‘was completed by a large team’ is the predicate. The verb is made up of two words: ‘was completed’.
Both examples above are complete ideas, and so they can stand on their own as sentences. We can say they are ‘independent’. However, in other sentences you may have a clause that is not a complete idea and so cannot stand on its own. In this case, we would say the clause is dependent, as it needs other information to truly make sense.
For example, in the following sentence we have one dependent clause that starts with ‘although’ and ends before the comma, and one ‘independent clause’ that starts after the comma:
Although the dog was big, it could run very quickly. ‘Although the dog was big’ is not a complete idea on its own, so it is a dependent clause. ‘It could run very quickly’ is a complete idea, so it is an independent clause.
Another name that you might hear for a dependent clause is ‘subordinate clause’ and another name you might hear for an independent clause is ‘main clause’. You can choose to use whichever names you prefer.
Think of the main/independent clause as the one that communicates the main message of the sentence. The subordinate/dependent clause is the one that adds extra information that is helpful, but not really critical, for communicating the main message.
Sentence Fragments
In a sentence fragment one of the key components is missing: it doesn’t have a subject, it doesn’t have a verb or verb phrase, or it is a dependent/subordinate clause on its own. This means a complete idea isn’t being presented. Below are some examples:
'While the second result was positive.' – This is a dependent clause on its own.
'Running in the park.' – This one doesn’t have a subject or complete verb phrase.
'The journalist in the first office.' – This one doesn’t have a verb
It is easier to understand a piece of writing when one idea flows to the next. One way we can achieve this is through using conjunctions and transition (or linking) words or phrases to link clauses and/or sentences. Different types of conjunctions and transition words have different effects. It is useful to gain an appreciation of what the different types of words do, and how to use them correctly, in order to increase the flow of your writing. Understanding the function of the different conjunctions also helps with punctuation.
Before reading on, make sure you are happy with what makes a clause and a sentence, which can be reviewed in the previous section.
Conjunctions
Conjunctions can be categorised into three types: coordinating conjunctions, subordinating conjunctions and correlative conjunctions. Each of these is explained further below.
1. Coordinating Conjunctions
These are the words that join two independent clauses (two complete ideas). They are the following:
For – to give an explanation or reason
And – to add something
Nor – to add an additional negative point
But – to give a contrasting point
Or – to give another option or possibility
Yet – to give a contrasting point
So – to give an explanation or reason
They are often remembered through the acronym FANBOYS. Examples of their use include:
'I completed the course but I didn’t get a time.'
'There was no evidence that the suspect committed the crime, so he was released.'
In both of these examples there are two complete ideas either side of the conjunction that could form sentences on their own. The second example uses a comma before the second clause. Commas can be used before any of these conjunctions.
2. Subordinating Conjunctions
These are conjunctions that start a subordinating clause (also called a dependent clause). There are more examples of this type of conjunction than coordinating conjunctions. They include words like although, whilst and if. They introduce extra information about a main clause that can often be non-essential, but may be useful in communicating the message (hence them being called subordinate). Examples include:
'Although I enjoy walking to work, I prefer to cycle most days.'
'Supposing that she breaks the record, what will be her plan after?'
'If I go to work early, I can also leave early.'
In these examples, the subordinating (dependent clause) comes first and the dependent clause second, but it could be the other way around. The clauses are separated by a comma. With conditional sentences, where one thing depends on another, as in the third example (they usually contain ‘if’), the clauses can be moved around but the comma would then be removed:
'I can also leave early if I go to work early.'
3. Correlative Conjunctions
These conjunctions are used to explain the relationship between clauses. They work in pairs. They include words like ‘either...or...’, ‘not only...but also...’, and ‘rather...than...’. Examples include:
'Either I go to work early or I come home late.'
'Not only was the food bad but it was also expensive.'
'I would rather play rugby than football.'
Transition Words
Transition words are adverbs that can be used to start a new sentence or independent clause and indicate that we are moving on to a new, but related, idea. They include words or phrases like ‘also’, ‘furthermore’, ‘in contrast’, ‘therefore’ and ‘in conclusion.’ It is also useful to make sure you are confident with using a range of words such as these in order to help make your writing flow. When written in a sentence, transition words are followed by a comma. Here are some examples:
'Also, there seems to be other factors influencing the results.'
'In contrast, the cost of the second design option is far cheaper.'
'Therefore, we can conclude that the policy was ineffective.'
Common Errors
People frequently use conjunctions and transition words incorrectly, which can easily confuse the audience. For example, they may use a word that indicates contrast when they want to indicate addition. For example:
'This was the main factor that influenced the result. Conversely, there was one other important factor.' – Incorrect
'This was the main factor that influenced the result. Additionally, there was one other important factor.' – Correct
Make sure you are confident about the meaning of the word before you use it.
People also overuse more informal expressions, such as ‘one the one hand’ and ‘on the other hand’, or use the same transition word or conjunction over and over again. This isn’t incorrect, but makes the writing less enjoyable to read, and so may impact the clarity of the text. To avoid this, try to vary the words that you use, or alternatively use colons and semi-colons to indicate relationships between clauses
There are four sentence structures that we can employ in English. Knowing about these can help make your writing more enjoyable to read and make sure your ideas have impact. It is also likely to prevent you from making grammar and punctuation mistakes, such as the comma splice.
The four types of sentence structure are as follows:
1. The Simple Sentence
This is a sentence with one independent clause. For example:
‘The hypothesis was shown to be correct’.
2. The Compound Sentence
This a sentence with two independent clauses joined by a coordinating conjunction (like ‘and, but, so, or, nor, as’). For example:
‘The experiments were costly and they took over 6 weeks to complete.’
3. The Complex Sentence
This is a sentence that has one independent (main) clause and one dependent (subordinate) clause. The dependent clause starts with a subordinating conjunction. For example:
‘Although the experiments were costly and time consuming, they gave useful results.’
4. The Complex-Compound Sentence (or Compound-Complex Sentence)
This is a sentence with at least one dependent clause and two independent clauses. For example:
‘Although the experiments were costly and time consuming, they gave useful results and meant that the researchers could move forward with their work.’
How the Structures Can Help Us
Once you have mastered using these sentences, you can then think about where in a paragraph it might be best to apply them. If you want to make your point clearly and give it a punch, then a simple sentence may be useful. This could be good to use at the end of a paragraph to summarise what you can conclude from that paragraph. The other types of sentences may be good to link ideas together. They could be used both between and within paragraphs.
Here are some examples in action:
'Although costs for the development are high, the disturbance to neighbours is also a significant factor. There will be large amounts of sound and air pollution as the development progresses, which will continue over a long period of time. Effects like this have been shown to impact upon people’s mental and physical health. There is also a school nearby that would be influenced by pollution and traffic. Therefore, careful consideration of the plans is needed.'
The first underlined sentence in the example above is a complex sentence that links the previous paragraph to this one. The other two underlined sentences convey important points that need to be made succinctly, so these have been made with simple sentences.