Sentence Errors

Sentence Run-ons

Sentences run on when two independent clauses aren’t joined properly. They should be joined with a semi-colon or a conjunction and a comma, or be two separate sentences.

X There has been a lot of research into the effects of recreational drugs it is inconclusive.
There has been a lot of research into the effects of recreational drugs; however, it is inconclusive.
There has been a lot of research into the effects of recreational drugs; it is inconclusive.
There has been a lot of research into the effects of recreational drugs, but it is inconclusive.
There has been a lot of research into the effects of recreational drugs. However, it is inconclusive.

Comma Splice

This is basically the same as a run-on sentence, but the writer has realized the need for some punctuation, but has incorrectly chosen a comma. There should be a conjunction as well, or a semi-colon instead of the comma.

X This new product we’re launching is faulty, it will have to be re-designed.
This new product we’re launching is faulty; it will have to be re-designed.
This new product we’re launching is faulty, so it will have to be re-designed.

Remember that adverbial conjunctions (however, consequently, therefore, moreover, nevertheless…) cannot appear in the middle of a sentence joined only by a comma. They either need to start a new sentence or follow a semi-colon.

X The government has introduced recycle bins, however this move is not enough to solve the growing refuse dilemma.
The government has introduced recycle bins; however, this move is not enough to solve the growing refuse dilemma.
The government has introduced recycle bins. However, this move is not enough to solve the growing refuse dilemma.

Sentence Fragments

A sentence needs a subject and a verb and must complete an idea. If any of this is missing, then what is left is only part of a sentence and needs to be fixed to make it whole. There are many things to look for to make sure that sentences are complete.

Verb missing

X Not understanding it impossible, he tried to do it anyway. (An –ing form - when not in a participle clause - needs an auxiliary verb)
Not understanding it was impossible, he tried to do it anyway.
X Our Chinese supplier unreliable.
Our Chinese supplier is unreliable.

Subject missing

X Even though working hard and doing long hours was good for future job prospects, was difficult and a strain on the family.
Even though working hard and doing long hours was good for future job prospects, it was difficult and a strain on the family.

X With company policies is hard to cover every eventuality.
With company policies it is hard to cover every eventuality.

Dependent clauses used incorrectly (sometimes due to conjunctions)

X To show how the magic trick was performed.
They replayed the footage in slow motion to show how the magic trick was performed.

X I am amused by the girl in our class. Who is always able to make up a good excuse for being late.
I am amused by the girl in our class who is always able to make up a good excuse for being late.

X Although tradition, which was very strong in the village, had always dictated that burial on the fourth day was the only correct form of interment. (Although… , …)
Although tradition, which was very strong in the village, had always dictated that burial on the fourth day was the only correct form of interment, it was decided he be buried today due to the imminent arrival of a hurricane, even though only two days of mourning had passed.

X The more that poverty is shown on television, people want to donate more money. (The more (–er )… , the more(–er) …)
The more that poverty is shown on television, the more people want to donate more money.

Phrases which are added to give extra information

These include descriptions, prepositional phrases and participle phrases. These may include a verb and/or subject, but they only modify something; they are not part of the real sentence. The best way to check a sentence including a modifying phrase is to cover that phrase and see if the rest of the sentence makes sense by itself. It should!

X Having to drive carefully in order not to have an accident in the extreme blizzard conditions. (This is a participle phrase that is only describing something but the subject hasn’t been introduced)
Having to drive carefully in order not to have an accident in the extreme blizzard conditions, Lucy tried not to think about her recently finalized divorce.

X At the time of the Industrial Revolution. (Extra phrase telling us when but there is no subject or verb)
At the time of the Industrial Revolution, a lot of young teenagers were leaving the country and heading for the cities.

Incomplete Verbs

This occurs when a person is confused about English tenses and their forms.

X The Christmas party was organised by Jo, but now that she’s left, someone else will have to take over and finish the preparations. (As the preparations are not finished, but were happening around a particular time in the past, the past continuous needs to be used. Think of the resulting sentence – Neil is organising the party now)
The Christmas party was being organised by Jo, but now that she’s left, someone else will have to take over and finish the preparations.\

X There were eight new toys for quality testing but only two tried. (The verb try should be passive)
There were eight new toys for quality testing but only two were tried.

A few other websites that deal with sentence problems.