Overview of Modality

What exactly does 'modality' mean? What's the relationship between - and the difference between - 'mood', 'modal', and 'modality'? How do we express modality, or know when modality is being expressed? What exactly qualifies as 'unreal mood'?
Mood is a tricky topic, and all of these questions will be addressed on this topic page.

What is 'Modality'?

Modality is an expression of the speaker’s level of conviction regarding whatever the sentence is talking about.  Consider the difference between these two sentences:

  1. “It’s going to rain today.”
  2. “I think it’s going to rain today.”


The first statement simply tells it like it is (presumably), while the second statement inserts the speaker’s thoughts or opinions into the matter.  While the first sentence is almost certainly a reflection of the speaker’s thoughts, that fact is not directly expressed in that sentence.  In other words, the speaker wants us to take “it’s going to rain today” as fact in the first sentence.  But for the second sentence, the speaker draws our attention to the fact that they’re expressing their own point of view.  This may be done out of humility or out of confidence, but either way, the speaker’s opinions are now a part of the conversation as but as the actual prediction of rain.

That first sentence has no modality; we call this indicative.  Meanwhile, the second sentence clearly has modality because of the phrase “I think …”.

Keep in mind that modality is all about perception and has nothing to do with reality.  Regardless of which of our two example sentences is expressed on any given day, it may rain, or it might not rain at all.  For the indicative sentence (sentence 1), the speaker’s perception is not stated and therefore irrelevant.  Usually, this means that it’s a true statement, but that’s not always the case; it’s possible that in saying, “It’s going to rain today,” the speaker is lying, or perhaps they are simply mistaken.  An indicative sentence is not necessarily any more true than a modal sentence.

How is Modality Expressed?

There are many ways to express modality, including:

  • Starting the sentence with phrases like “I think …”, “I wonder if …”, “I bet …”, “I imagine …”, “I believe …”, and so on.
  • Using a modal verb at the start of the verb phrase.  Modal verbs are auxiliary verbs that communicate modality.  The principal modals are can, could, may, might, must, shall, should, will, and would.  The different modals express various levels of conviction.
  • Inserting an adverb of modality into the sentence.  Modal adverbs include probably, possibly, maybe, presumably, certainly, undoubtedly, potentially, surely, likely, allegedly, clearly, apparently, evidently, obviously, reportedly, hypothetically, and so on.  Such adverbs typically come either at the start of the clause or before the main verb (but after its helping verbs).
  • Using a modal adjective like conceivable, possible, unlikely, and so forth, especially in an introductory phrase like, “It is ____ that …”.
  • Through some Infinitive Verb Patterns, especially when combined with Passive Voice, as in “was commanded to …” or “is expected to …”.
  • With deviations of standard sentence structures, such as in word order (eg. “Had I known …”) or in subject-verb agreement (eg. “If he be worthy …”).  Such methods are fairly uncommon even among advanced speakers.

Mood, Modality, & Modals

You may have noticed that the term ‘modal’ appeared a few times in the previous section, and it should be clear that ‘modal’ and ‘modality’ have the same root.  While ‘modality’ is the concept, ‘modal’ is a property of different parts of speech that express the modality concept.  Modal verbs, modal adverbs, and modal adjectives can all indicate that the verb phrase — or the entire clause — has modality; in the same way that a sentence has modality if it includes the phrase “I think”, it also has modality if it contains words like “may”, “likely”, or “probable”.

By the way, when the term ‘modal’ stands alone, it almost always means ‘modal verb’.

Another word with the same root as ‘modal’ and ‘modality’ is ‘mood’.  The mood of a verb phrase is the speaker’s attitude toward the situation.  The mood can feature modality, or it can have the lack of modality (which, again, we call ‘indicative mood’).

In English, the primary moods are realis (real) and irrealis (unreal).  We can break these down into sub-moods like ‘indicative’, ‘imperative’, and ‘subjunctive’.  Certain other languages have many more sub-moods which may affect the grammar of a sentence, but the distinction between some of those moods is less clear in English.  For English language teaching, we rarely need to consider anything deeper than Real Mood and Unreal Mood.

Applications of Modality

When we’re not simply stating (or asking) how things are at the relevant moment, we might focus instead on:

  • How we think or believe things to be.  For example:
    • “It’s expected to rain tomorrow.”
    • “It’s probably raining in Seattle right now.”
    • “It must’ve rained last night; the ground’s still wet.”
  • How we want things to be or think they should be.  For example:
    • “I hope it doesn’t rain anytime soon.”
    • “It must rain this week in order for our crops to have any chance of survival.”
  • How things can be and sometimes are.  For example:
    • “It tends to rain a lot more in monsoon season.”
    • “It rains frequently up in these mountains.”
    • “It can’t rain at the South Pole.”

Check out the Flavors of Modal Verbs topic page for more.

When we say that modality expresses the speaker’s level of conviction, keep in mind that runs the whole length of that spectrum.  Frequently, modality expresses a certain degree of uncertainty (words like should and probably have a great deal of conviction, but are not 100%).  But they could express a complete lack of conviction.  Alternatively, they could express total conviction (like with the words must and certainly), in which case they are arguably stronger statements than indicative (non-modal) statements, depending on the situation.

Modality & Unreal Mood

When we express anything other than how things are, we use the Unreal Mood.  The Unreal Mood is perhaps best exemplified in hypothetical statements and questions.  For instance, “Which book would you bring with you to a deserted island?” or “I wish I had superpowers,” are clearly not real situations.  But unreal does not necessarily mean impossible or infeasible.

  • Expressions of probability (like “Her parcel should arrive soon,”) — even if they are incredibly likely and realistic — are unreal until their outcome is confirmed.
  • Expressions of commands or regulations are unreal.  We typically say how things should be when it’s understood that it’s not how they are, at least at the time.  Even imperative sentences (like “Go to your room right now!”) are unreal since their directions have not yet been followed.
  • Expressions of ability and tendency may or may not be unreal; this idea has not yet been settled among linguists. Consider an expression of how things sometimes are.  On one had, they’re not necessarily expressing how things are at the moment, which makes it unreal.  On the other hand, the presumably do happen sometimes, making it real.  Don’t worry, this distinction is probably not important for TEFL.
  • Most expressions for the future could arguably be considered unreal.  Using terms like will and be going to express plans and predictions, which are not indicative.  The exception would be future appointments expressed through the present simple or present continuous tenses.
With such a strong correlation between expressions of modality and the Unreal Mood, you can expect to find and use modality in grammar topics like Conditionals and Wishes & Regrets.

Keep on Learning; Keep on Teaching

Modal Verb Flavors

Modality is perhaps most commonly expressed through Modal Verbs. The different flavors express different styles of modality.
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Content Clauses

Clauses like "I think ...", "I wonder if ...", and "It's possible that ..." are followed by content clauses.
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