Common English Errors
in Masters' Theses

By professor Jacob Palme,
Department of Computer and Systems Sciences
KTH Technical University



Here are some common mistakes in the use of the English language by Student's writing Master's theses.


Ask someone else to check


Ask someone else to read your texts. You are blind to your own English-language errors.


Spell checking


Run a spell checker, before submitting your texts to anyone else for reading.


Etc., I.e., E.g., However, Indeed, Too


"Etc." should in English always be preceded by ", ". It usually ends a sentence, but if not, there should be a second comma after "Etc.". The same rule applies to "However". In the case of "i.e." and "e.g.", they should be preceded by a comma, but need not be followed by a comma.


Sheep, cows, tigers, etc., are, however, animals.




In English, you should not omit the period after abbreviations, like some people do in Swedish. Acronyms, however, can be written with or without periods.


"USA" and "U.S.A." are both correct English.

Both "7 p.m." and "7 PM" are correct, but "7 p m" is not correct.


Can't, Doesn't, We're, it'll


"Can't" and "Doesn't" and similar constructs are spoken language, in serious written text use "Cannot" and "Does not".


Sheep cannot fly, they do not have wings.




"E.g." should usually be avoided, in serious written text use "Example" or "Examples" or "Like".


Mammals, like humans and tigers, are warm-blooded animals.

Note also that Swedish "alltså" is in scientific English text represented by "i.e.". "I.e." can also mean "more precisely".


The summer, i.e. from June to August, is warm.


"A" and "An"

 The choice between "a" and "an" is made based on the pronunciation, not the spelling, of the next word. Thus, you write "An MTG shareholder", not "a MTG shareholder", because "MTG" is pronounced "em-tee-gee". 

Genitive Apostrophe


It is easy for a Swede to forget the genitive apostrophe, because we do not use it in Swedish.


Marie's pet is a cat.


Non-sexist Pronouns


Use plural sense to avoid sexist pronouns.


Not good: If someone is ill, he must lie in bed

Good: If people are ill, they must lie in bed.

Note: It is legal, and becoming more and more common, to use the word "they" also in singular.


If a citizen does not submit their income tax report, they are charged a surcharge of $500.

More info.


Check that the Sense of Subject and Verb Agree


Check that the sense of subject and verb agree.


Birds, which live in the forest, find food in the trees.
The city sleeps.
Androids dream of electric sheep.
John and Mary are there.
Either John or Mary is there.