Modal Expressions
Academic discourse is mostly about theories, conclusions drawn from evidence exchanging viewpoints, etc, so claims and statements are not too direct and assertive (hedging). Less often, the viewpoint needs to be asserted directly and confidently (boosting). Hedging and boosting are basically realized through modal expressions.

REFERRING FORWARD
  • will and may are associated with the future, as they are used to predict. Referring to the past, modal verb+perfect auxiliary+ past participle of the verb – it might have happened,
  • to be going to is often used for forward reference in spoken academic style.
 
HEDGING
  • may, might are used to state possibilities,
  • can is used to make firmly confident, but not absolute assertions,
  • be + likely + infinitive is used to state probability,
  • would is used to hedge assertions,
  • should is used to hedge conclusions and predictions.
 
BOOSTING
  • certainty: auxiliary (will, must, have to) + verb or adverb+verb certainly, definitely, clearly, obviously, really),
  • impossibility: cannot.
 

Hedging and boosting in academic texts are often carried out by the use of a range of adverbial and prepositional constructions, e.g. apparently, evidently, roughly, seemingly as hedging expressions and clearly, definitely, inevitably, obviously, undoubtedly as boosting expressions.

Impersonal it-constructions (it is suggested, it is claimed, it is believed with the passive) help avoid the direct commitment to a proposition.