The Use of Formal and Informal Language in Dissertations/Essays

An informal style of writing that involves the use of colloquialisms and slang language is often suitable for journalistic reports, novels, or books. However, it is not considered appropriate for a master's or PhD thesis, journal article, or other scientific or scholarly paper. Essays and theses/dissertations must always be written in formal academic English.

In this context, universities, academic institutions, and journal article publishers set a specific standard for the formal language used in academic manuscripts.

First, it is important to define precisely what is meant by formal and informal language.

The Cambridge Dictionary offers the following comparative definition:

‘We use formal language in situations that are serious or that involve people we don’t know well. Informal language is more commonly used in situations that are more relaxed and involve people we know well. Formal language is more common when we write; informal language is more common when we speak. However, there are times where writing can be very informal; for example, when writing postcards or letters to friends, emails or text messages. There are also examples where spoken English can be very formal, for example, in a speech or a lecture. Most uses of English are neutral; that is, they are neither formal nor informal. Formal language and informal language are associated with particular choices of grammar and vocabulary.

Contractions, relative clauses without a relative pronoun and ellipsis are more common in informal language.’

The Oxford Dictionary expands further on the definition of formal language:

‘You tend to find formal language in academic journals or official documents and notices where it brings an extra degree of seriousness to the subject. As a general rule, it isn't appropriate for everyday situations. It can be tempting to use formal vocabulary in the hope that it will add more weight to what you are saying, or just sound generally more impressive or sophisticated. You should generally try to resist this temptation. Using formal English in everyday situations can make your writing sound pompous or pretentious. You may also make what you've written sound unintentionally funny, as some writers deliberately choose formal vocabulary to create a comic effect.’

What are the precise differences between formal and informal language?

a) - Contractions

The first difference between formal and informal academic language relates to the use of contractions. A contraction is basically a simplified form of two words merged into one and is common in informal writing. However, when writing your dissertation/thesis or any other academic paper, use the full form of the two words: DO NOT use contractions!

Examples of appropriate phrases to use (with the corresponding contractions in brackets) are presented below:
They have (they've)
We are (we're)
They do not (they don't)
I had better (I'd better)
They would (they'd)
They shall (they'll)
She is (she's)

b) - Phrasal verbs

What is a phrasal verb?
Simply put, it is a verb that consists of two or more words. Some common examples are presented below:
Carry out
Set out
Go beyond
Sweep across
Lay out
Go through

The authors of academic papers, dissertations/theses, or essays are NOT expected to use phrasal verbs in their writing.

What should they do instead?
The answer is to simply use single-word verbs, as shown in the following examples:
Instead of carry out, use conduct, perform, execute (depending on the context).
Instead of go beyond, use exceed, transcend, surpass (depending on the context).
Instead of go through, use experience, suffer, undergo (depending on the context).
Instead of give rise to, use cause, engender, induce (depending on the context).
Instead of point out, use highlight, state, note (depending on the context).
Instead of look for, use seek, pursue (depending on the context).

c) Do not end the sentence with a phrasal verb/preposition

It is considered particularly inappropriate to use a phrasal verb at the end of a sentence, or indeed finish the sentence with a preposition, as shown in the following examples:
The researcher has decided on the experiment that he will carry out (a phrasal verb).
This chapter discusses what the participants in the study went through (a phrasal verb).
This essay aimed to discuss the phenomenon in depth and this is what the author was praised for(finishing on a preposition).
This weakness in the thesis defence is what he was criticised for (finishing on a preposition).

Acceptable versions of these sentences are as follows:

The researcher decided to conduct the following experiment.

This chapter discusses the experiences of participants.

The researcher was praised for discussing the phenomenon in depth.

He was criticised for the weakness in his thesis defence.

d) Formal vs informal words

In English, there are simply words that are formal and others that are informal. MA or PhD students writing their dissertations or essays or journal article authors must always stick to using formal words.

Below are some of the most common examples:

kids (informal) vs children (formal)
huge (informal) vs enormous (formal)
big (informal) vs considerable (formal)

bad/good (informal) vs positive/negative (formal)
buy (informal) vs purchase (formal)
make (informal) vs produce/manufacture (formal)
many (informal) vs numerous/multiple (formal)
choose (informal) vs select (formal)
maybe (informal) vs perhaps (formal)
see (informal) vs observe (formal)

old (informal) vs dated (formal)

It is especially important to use formal versions of words that indicate transitions in a sentence, common examples of which are as follows:

plus (informal) vs moreover (formal)

so (informal) vs therefore/hence (formal)
also (informal) vs additionally (formal)

but (informal) vs however (formal)

in a nutshell (informal) vs in sum (formal)

and then (informal) vs furthermore (formal)

Have you written a dissertation/thesis, essay, or article and are not sure whether your language is formal enough? Need a professional academic editor or proofreader to scrutinise your paper for any instances of informal language? Do not worry, you are in safe hands!

The Ultimate Proofreader is a UK provider of specialist academic proofreading services. We offer excellent proofreading services for dissertations, essays, and academic journals.