What is a sentence?
A sentence is a group of words, almost always
containing at least one subject and one verb, which expresses a complete
thought or idea. Sentences always start with a capital letter, and always
end with a full stop, a question mark or, in more informal writing,
an exclamation mark.
Why are sentences important?
In more formal written English clear structure
is of paramount importance, and sentences are the foundation to achieving
this. Unlike in spoken English, where the listener’s understanding
is greatly aided by intonation, facial expressions and body language,
and where repetition, vagueness and uncompleted ideas are perfectly
acceptable, in order to express yourself in formal written English you
must write in clear, concise, complete, well-punctuated sentences.
What errors are made in
There are four types of errors made when
Sentences are incomplete
Look at the following example:
We decided to go out for a
walk. Although it was raining.
The second sentence here is incomplete, as
it does not make sense by itself; it is in fact part of the first sentence.
These are often referred to as sentence fragments.
Sentences are incorrectly punctuated
This is usually a question of poor use of
commas. A fairly common problem are what are called run-on or comma-spliced
sentences. This is when the writer separates two or more individual
simple sentences with a comma, when what is needed is a linking word
such as and, but, or however (See Guide 1.39), as semi-colon ( ; ) or
a colon ( : ), or separate sentences altogether.
I went to a party last night,
I left early because I didn’t feel well.
I went to a party last night but left early
because I didn’t feel well.
Alternatively, commas may not be used at
all, or used in the wrong place.
Sentences are too long
The longer your sentence, the more control
you need over punctuation, linking words, and use of pronouns. If you
use any of these badly, then your reader will become confused. The last
thing you want is for your tutor, getting through a pile of 50 essays
at midnight, to have to start reading a sentence three or four times
to try and make sense of it. It is therefore usually recommended that
you write in fairly short sentences, maybe a maximum of around 20-25
words or a couple of lines. As you get more practice and your writing
improves, you can start to make your sentences longer.
Sentences are too short
Don’t go to the opposite extreme and
write lots of very short sentences of just a few words. Your writing
will become “bitty”, and again will become tiring for the
reader. Occasional short sentences can be very effective to emphasise
a point, but don’t put lots of them together.
There is more detail on these four
points later in this guide.
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Types of sentences
Sentences are made up of clauses.
A clause is a group of grammatically-related words including a verb
and a subject (though sometimes is the subject is implied). Clauses
are the building blocks of sentences: every sentence consists of one
or more clauses. In more complex sentences there is always a main clause,
together with one or more relative or subordinate clauses. And getting
even more technical, clauses can be finite or non-finite. Finite clauses
are based on verbs which indicate tense, such as “saw” or
“will go”, whereas non-finite clauses are based on infinitives
(the base form of the verb, such as “consider”) or participles
(for example, “taking”).
Simple sentences contain just one finite clause and express just one
idea or provide just one piece of information.
They can be very short:
I passed the test.
Or much longer:
Living only 3km away from the University on a main bus route, he
was able to get to his lecture in just 15 minutes.
In this second example, 24 words long, the first clause is non-finite
(living), while the second is finite (was able to). Although a longer
sentence, it still just expresses one piece of information.
These sentences contain two or more simple sentences, or independent
clauses, joined by conjunctions such as or, but or and or by a semi-colon
or a colon.
They can have one subject and two verbs:
Birmingham City University is a modern university and is spread over several campuses.
Birmingham is the second biggest city in the UK; it is situated in the
centre of the country.
Or two subjects (or a repeated subject) and two verbs:
I decided to have a gap year before starting my degree course, but
most of my friends went straight to university.
It was the best concert I had ever been to: Tom Waits sang magnificently.
Remember not to separate the two parts of these sentences with just
Complex sentences consist of two or more clauses, but unlike compound
sentences in which the clauses are “equal” and can be independent,
in this type of sentence they are not equal; there is a main clause,
a simple sentence which can be independent, with other clauses dependent
or subordinate on it. These clauses do not make complete sense by themselves
and are joined to the main clause by linking words or phrases such as
the conjunctions although, because, when, if etc. They have one finite
verb and their function is to give reasons, conditions, concessions,
times of action etc.
If England keep on playing in the same manner, they won’t
win the World Cup.
Here, the first clause (If England ...), although the longer of the
two, is dependent on the second clause, which is the main one. If
England keep on playing in the same manner doesn’t make complete
sense by itself, whereas they won’t win the World Cup
does. The second part, therefore, is clearly the more important piece
of information, while the first part is just one of the conditions,
or in this cases reasons, for saying this.
Although the workers have been given a 7% pay rise, they are still
not happy with their situation.
We left for the airport two hours earlier than usual because the baggage
handlers were threatening strike action.
Your aim should be to use a variety
of sentences in your writing:
Short simple sentences
grab the reader’s attention and add emphasis.
Compound sentences can
emphasise balance and parallel ideas.
Complex sentences show
what information depends on what other information.
Complex sentences can often be written
“the other way round”:
If I win the lottery, I’m going to retire.
means more or less the same as
I’m going to retire if I win the lottery.
The only difference is one of emphasis (and a comma in the first version).
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Avoiding sentence fragments
Sentence fragments usually occur when a sentence is prematurely brought
to an end and a new sentence unnecessarily started. This new sentence
very often begins with a conjunction such as although, if, however,
but etc. and is in fact a dependent clause which needs the other
part of the sentence to make sense.
A reason some people write sentence fragments, therefore, may be that
they think conjunctions always come at the beginning of a sentence.
This is not true.
Sentence fragments also occur when a non-finite clause is made into
a simple sentence. For example,
Considering the complexities of the application procedure.
is not a sentence. The participle considering by itself does
not indicate tense; we do not know if the writer is referring to the
past, present or future. This non-finite clause needs an additional
finite clause in order to make sense:
Considering the complexities of the application procedure, it is
surprising how many people do apply for a loan.
Here are some more examples of sentence fragments; try and rewrite
them as complete sentences.
1 A franchiser can achieve wide distribution. As each franchisee has
to buy stock from the franchiser.
2 In order to succeed in business internationally. The manufacturer
must find out about local markets.
3 Minimum wages could help to increase income because if wages are low,
production will be high and cost prices will be reduced. Resulting in
an increase in the company's income.
4 If everyone earns the same amount of money. At the end of the day,
whether you have skills or not, the wages will be the same.
5 Settings should be made at 15.8 – 16.2 cm. Allowing for natural
variations and differing
6 When the first UK McDonald's opened in 1974 in London. A totally new
eating experience arrived in this country.
7 First of all. The general socio-economic climate in the UK encourages
8 Due to the increase in payment by card. Mondex stands a good chance
of being widely accepted.
9 If the trademark and location are both very attractive. There will
be a lot of replies.
10 Starting with the first example. It has been shown that extensive
revision does not always lead to success.
11 According to Walsh (1990), the number of employees in part time employment
increased from 15% in 1971 to 30% by the mid-1990s. While findings by
the Institute of Manpower Studies (1985) found the proportion of women
part-timers grew from 38% to 46% between 1974 and 1985.
12 The core group of the company comprises senior employees who possess
particular skills. Such as marketing managers, sales staff, IT experts
and distribution management.
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Sentences of this type have at least two parts, either one of which
can stand by itself (in other words, two independent clauses), but the
two parts have been merged together instead of being properly connected.
The length of a sentence has nothing to do with whether a sentence is
a run-on or not; being a run-on is a structural flaw that can plague
even a very short sentence:
It’s raining, take you umbrella.
An extremely long sentence, on the other
hand, might contain a lot of waffle, but it can still be otherwise sound
When you use a comma to connect
two independent clauses, it must be accompanied by a conjunction (and,
but, for, nor, yet, or, so).
It’s raining, so take your umbrella.
Run-on sentences happen typically
under the following circumstances:
a. When an independent clause gives an order or directive based on what
was said in the prior independent clause:
This next chapter has a lot of difficult information in it, you should
start studying right away.
(We could put a full stop where
that comma is and start a new sentence. A semicolon might also work
b. When two independent clauses are connected by a transitional expression
(conjunctive adverb) such as however, moreover, nevertheless.
Mr. McGrath has sent his four children to independent schools, however,
he has sacrificed his health working day and night in his factory.
(Again, where that first comma appears,
we could have used either a full stop — and started a new sentence
— or a semicolon.)
c. When the second of two independent clauses contains a pronoun that
connects it to the first independent clause.
This computer doesn't make sense to me, it came without a manual.
(Although these two clauses are quite brief, and the ideas are closely
related, this is a run-on sentence. We need a full stop where that comma
Most of those computers in the Learning Centre are broken already,
this proves my point about British computer manufacturers.
Again, two nicely related clauses, incorrectly
connected — a run-on. Use a full stop to cure this sentence.
Adapted in part from: http://webster.commnet.edu/grammar/runons.htm
The following sentences are all run-ons.
Try to devise two different ways to correct each one.
1. The co-op board voted to fine the tenant
for noisiness, it is not clear whether he violated any established rule.
2. Tom was always late for his legal seminar
he knew it annoyed the professor and would affect his grade but he just
couldn’t get up on time.
3. The defendant will argue that she had
no knowledge that the merchandise was stolen however, the evidence indicates
4. The mortgage company refused to issue
a refund check for excess funds in the Smiths’ escrow account,
this violated the law.
5. The textbook gives many examples
of run-on sentences, there is no answer key, how can we check our answers?
Exercise source: http://www.law.cuny.edu/wc/usage/run_on_sentences.html