Tense, Aspect, and Modality as Discourse Resources

Tense, aspect, and modality are often introduced as separate areas of grammar. Learners may study past and present tenses in one unit, progressive and perfect forms in another, and modal verbs such as may, should, and must somewhere else. From a discourse perspective, however, these forms are more interesting when we examine how they work together across a complete text. Speakers and writers use them to establish time frames, organize events, highlight changes, express attitudes, and indicate different degrees of possibility, certainty, or obligation. In this sense, tense, aspect, and modality contribute to coherence, helping readers and listeners understand how one part of a discourse relates to another. Celce-Murcia and Olshtain (1999) specifically describe tense, aspect, and modality as resources for organizing coherent discourse rather than merely as sentence-level grammar.

Tense: Establishing and Moving Through Time

Tense helps establish the temporal location from which events and situations are viewed. At the sentence level, students may simply identify a verb as past or present. At the discourse level, a more useful question is: Why does the speaker or writer choose this tense at this particular point in the text?

Consider the opening of the study-habits text:

When Mariana first entered university, she used to study only the night before an examination.

The expression used to study immediately establishes a past habitual frame. It tells us not simply that Mariana studied in the past, but that this behavior characterized an earlier period of her life. The following sentence continues:

She would sit at her desk for several hours, rereading her notes.

Here, would sit elaborates the habitual frame already established by used to. This pattern reflects an observation highlighted by Celce-Murcia and Olshtain: in past habitual narratives, used to frequently establishes the rhetorical frame, while would develops or elaborates the activities within that frame. Simple past forms may then appear to provide particular events, evaluations, or background information.

This distinction demonstrates why discourse analysis goes beyond asking whether two grammatical forms are technically possible. The forms perform somewhat different jobs in organizing the text. Used to introduces the former situation; would helps the writer expand it.

Aspect: How the Writer Views an Event

While tense helps locate situations in time, aspect concerns how the speaker or writer chooses to view those situations. An event can be presented as a whole, as ongoing, as completed with relevance to another time, or as continuing across a period.

The study-habits text moves from Mariana’s former behavior to her present situation:

Her study habits have changed considerably since then.

The present perfect connects the past with the present. The change began before the moment of writing, but its result matters now. The next two forms develop this temporal perspective:

She has developed a weekly study schedule, and she has been reviewing her notes for about thirty minutes each evening.

Has developed presents the development as an accomplishment with a present result. Has been reviewing, by contrast, emphasizes an activity extending over time. The perfect progressive therefore encourages readers to view the studying as an ongoing pattern rather than simply as a completed event.

The text then moves closer to the immediate present:

This week, she is preparing for three examinations, so she is spending more time in the library than usual.

The progressive aspect presents these activities as currently unfolding and temporary. The sequence from used to study to has changed, has been reviewing, and is preparing creates a meaningful progression from past habit → change over time → current activity. This is precisely the kind of discourse-level function emphasized in the course: tense and aspect organize time, foreground events, and guide interpretation across extended discourse.

Modality: Expressing Stance Toward What Is Said

Modality introduces another dimension. Instead of primarily organizing time, modality shows how a speaker or writer positions themselves toward a proposition or toward another person. It can express possibility, prediction, ability, recommendation, necessity, or obligation. In the course framework, modality is therefore closely connected with stance and interpersonal meaning.

Notice how the middle paragraph of the sample text changes from describing Mariana’s behavior to evaluating study practices:

Students should develop regular study routines.

Here, should presents a recommendation rather than an objective fact.

One strategy may not work equally well for everyone.

May weakens the certainty of the claim and acknowledges other possibilities.

Some students might need complete silence.

Might again expresses possibility rather than certainty.

Others can concentrate better with background music.

Here, can expresses ability or possibility.

Finally:

Students must decide which conditions help them learn most effectively.

Must creates a much stronger sense of necessity or obligation. The sequence therefore moves through different degrees of writer commitment. Modality allows the writer to avoid treating every statement as equally certain or equally forceful. This is particularly important in academic and educational discourse, where writers constantly manage certainty, authority, caution, and relationships with readers.

Combining Time and Stance

Tense, aspect, and modality frequently operate together rather than independently. The final paragraph demonstrates this interaction particularly clearly:

Next semester, Mariana is going to experiment with a study group. She thinks the group will help her, although it might also create new distractions.

The first form establishes a future scenario. Celce-Murcia and Olshtain note a discourse pattern in which be going to introduces or frames a future scenario and will subsequently helps elaborate it. In the sample, is going to experiment establishes the future plan, will help develops an anticipated consequence, and might create introduces uncertainty about another possible result.

The final form adds yet another temporal perspective:

By the end of the academic year, she hopes she will have developed a flexible system.

The future perfect asks readers to look backward from a future reference point and imagine the process as completed by then.

The important lesson for discourse analysis is therefore not simply to identify grammatical forms. Learners should ask what each choice contributes to the developing text. Tense establishes and shifts temporal frames. Aspect shapes how events and situations are viewed. Modality reveals the speaker’s or writer’s degree of certainty, possibility, authority, or obligation. Together, these grammatical resources help transform separate sentences into an organized discourse in which time, perspective, and stance develop coherently.