Academic Writing:Expressing Opinion:Modal verbs and adverbs

The table below contains verbs and adverbs that you can use to express the different degrees of certainty or modality of your opinions or argument. It also provides you with some examples of how to structure your sentence to use these words in your writing.

Certainty of Conclusion	Modal Verbs/Adverbs	Statement of Claim
Strong	is, will, can not, must, undoubtedly, always, never, definitely, clearly	It is certain that... It seems clear that... X is definitely...
Moderate	should, would, can, ought to, tends to, usually, likely, probably, regularly, majority, generally, often, frequently, rarely	It appears probable... It is usually the case that... In the majority of cases... The results suggest it is likely that...
Tentative	May, might, could, possible, conceivable, sometimes, occasionally, seldomly, perhaps, maybe, uncertainly, minority	Conceivably,... It is possible that... Occasionally,... It may be the case that...

Adapted from: Jordon, R. R. (1990) Academic Writing Course. Edinburgh: Nelson Study Skills in English and Learning Assistance Centre, University of Sydney (1992) Writing in an Academic Style.

It seems likely that a species leaf structural characteristics influence their seasonal water-tissue relations because……	Low modality - rather than 'it is the case', the author is less certain, 'it seems likely it is the case'.
Technology assessment can be an effective tool to analyse the effect of a technology on social and environmental issues, yet in practise it can be used to formalise and legitimise previously decided outcomes.	More moderate expression of opinion than saying 'is'.
Legal aid, by providing representation and individual legal advice has the potential to mitigate some of the entrenched inequality in regards to access to justice.	Modality lowered through the use of 'has the potential to' rather than merely 'it mitigates’.
The large-scale treatment plant is the most desirable option to provide for the processing and treatment of wastewater for a 20 000 person population.	The opinion expressed in this sentence is strong, however, it is more moderate than saying '…is the only appropriate option…’

Ultimately, your opinion in academic writing must be based on the evidence you have collected. The level of modality used to express your opinion must match the level of certainty provided by your evidence. It might be appropriate to make a high modality claim because evidence, from multiple sources, backs up your opinion. Therefore, adjust the certainty or modality you use to present your argument according to the quality and amount of evidence supporting it.