One of the most common difficulties that people have when writing in English is using commas. This tricky little piece of punctuation trips up the majority of native speakers, as well as those English learners who take tests like OET. While there are some complexities to comma use, learning the basics isn’t actually that hard, and in today’s article we will look at some of the ways you might have to use commas in order to do well for your OET writing sub-test.
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Rules of Comma Use
In the sections below, I will outline some common uses of the comma pertaining to the OET writing sub-test. Obviously, there are many cases when a comma could be used, so it is important to do more in-depth research. This list is just a starting point on the road to fully mastering the comma.
1. Complex Sentences
A complex sentence is made up of two clauses, one of which is independent and the other is dependent. Either clause can be put first or second in the sentence, but that will change the punctuation that is used:
Independent clause + dependent clause
Dependent clause + comma + independent clause
- Treatment will begin after a full diagnosis is made.
- After a full diagnosis is made, treatment will begin.
- Upon examination, we found that she could hardly see.
- Due to non-compliance with medication, the patient’s symptoms were aggravated
2. Compound Sentences
Compound sentences are made up of two or more independent clauses. In most cases, these are joined by a comma and a coordinating conjunction (for, and, nor, but, or, yet, so).
Independent clause + comma + coordinating conjunction + independent clause
- The cause of her headaches was unknown, so Mrs. Trafford was sent to the specialist.
One thing to note is that sometimes when these sentences are very short, the comma is omitted.
Compound sentences can also be joined by a semi-colon and conjunctive adverb. In this case, the comma appears after the conjunctive adverb and before the second independent clause:
Independent clause + semi-colon + conjunctive adverb + comma + independent clause
- The cause of her headaches was unknown; therefore, Mrs. Trafford was sent to the specialist.
A few common errors exist for comma use, and some of these relate to compound sentences. One of the biggest and most frequent errors is called the comma splice. This means using a comma to separate two independent clauses when there is no coordinating conjunction. That mistakes looks like this:
- Eye drops were administered, the patient was told to return several days later.
This could be fixed by simply adding a coordinating conjunction:
- Eye drops were administered, and the patient was told to return several days later.
The mistake can similarly be made with a conjunctive adverb if the semi-colon is replaced erroneously by a comma:
- The patient was overweight, therefore, she was advised about diets.
- The patient was overweight; therefore, she was advised about diets.
3. Introductory and Transitional Phrases
There are various kinds of phrases that go at the beginning of a sentence in English, often before the subject. These serve different purposes, but generally speaking they all take a comma between them and the subject of the sentence (which begins a new clause). These phrases generally introduce something or offer a transition between different ideas.
Transitional phrase + comma + main clause
- On October 14th, Mrs. Parker underwent surgery for a broken ankle.
- As a result, she was unable to continue working.
- On examination, it was found that the patient was allergic to penicillin.
4. Lists of Ideas or Items
In English, it is possible to list ideas or items in a sentence if they are separated by commas. Each item should be clearly set apart from the others by a comma, including the final item, which would also have the word “and” or “or” setting it apart. The structure looks like this:
Item 1 + comma + item 2 + comma + and/or + item 3
This final comma is known as the “Oxford comma” and it is the correct way of punctuating lists. Some people do not use this, but they are mistaken. It greatly increases the clarity of a piece of writing.
- The patient was advised to take painkillers, antibiotics, and get plenty of bed rest.
Look at the following passage. Read it carefully and fix the problems concerning commas.
- The patient has an allergy to latex and is currently taking Xanax for anxiety. Last year she had surgery on her left knee which has fully healed now. Although she is slightly overweight she has lost weight over the past six months and is making good progress. She takes regular exercise, however, she drinks on the weekend.
The patient has an allergy to latex, and is currently taking Xanax for anxiety. Last year, she had surgery on her left knee, which has fully healed now. Although she is slightly overweight, she has lost weight over the past six months and is making good progress. She takes regular exercise; however, she drinks on the weekend.