What is Grammatical Mood?

Before we dive in, let’s clarify what we mean by “mood.” In grammar, mood (or modality) refers to the way a verb expresses a speaker’s attitude toward the factuality or likelihood of the proposition they are stating. It’s different from tense (which marks time) and aspect (which marks duration or completion).

Think of it as a status tag on a verb. Is the action being presented as a fact? A command? A possibility? A wish? That status tag is its mood. Many languages have an overarching, binary way of sorting these tags into two fundamental baskets:

• Realis Mood: Used for situations that are asserted as real, factual, and known. These are events that have happened or are currently happening. The speaker commits to their reality.
• Irrealis Mood: Used for situations that are not asserted as real. This is a broad category for everything non-factual, including hypotheticals, futures, desires, commands, possibilities, and negated statements. The speaker does not commit to their reality.

For speakers of a language with a strong realis/irrealis distinction, you can’t just state an action. You are grammatically forced to declare its relationship to the real world every time you conjugate a verb.

The Wide World of the Irrealis

The realis category is straightforward: it’s the world of facts. The irrealis, however, is a vast and varied landscape of unreality. It’s a grammatical super-category that often includes several distinct modes of thought we might otherwise consider separate.

Common Irrealis Categories:

• Hypotheticals/Conditionals: “If I were a rich man…” The classic “what if” scenario.
• Futures: “I will go to the store.” In many languages, the future is inherently irrealis because it has not yet happened and is therefore not a settled fact.
• Desires/Wishes (Optative/Desiderative): “I wish it would rain.” or “If only he knew.” These are explicitly contrary to present reality.
• Commands/Requests (Imperative/Jussive): “Go to your room!” A command is irrealis because the action has not yet been performed; it is a desired outcome.
• Abilities/Potentials (Potential): “She can speak four languages.” Her potential to speak them exists, but she isn’t actively speaking all four right now.
• Negation: “He did not eat the cake.” The action of eating is framed as a non-event, placing it in the realm of the unreal. In many languages, the verb marking for a negative sentence is the same as the one used for hypotheticals.

How Do Languages Mark This Distinction?

This is where it gets fascinating. Languages have different strategies, ranging from a “grammatical toolkit” like in English to a single, explicit marker.

English: A Collection of Tools

English does not have a single, unified realis/irrealis verb ending. Instead, we use a patchwork of different grammatical tools to express irreality:

• Modal Verbs: This is our primary strategy. The difference between “I walk” (realis) and “I might walk”, “I could walk”, or “I should walk” (irrealis) is carried entirely by the modal verb.
• The Subjunctive Mood: A remnant of a more robust mood system, the English subjunctive signals irreality. It’s most famous in conditionals: “If I were you…” (not “If I was you…”). The use of “were” instead of “was” is a pure irrealis marker, telling the listener that we are in a hypothetical space.
• The “Will” Future: Our future tense using “will” conceptually places future events in the irrealis camp, as they are not yet factual.

Because our system is fragmented, English speakers often don’t think of “I wish” and “Go away!” as being grammatically related. But from a realis/irrealis perspective, they are two flavors of the same thing: non-factuality.

Manam: A System Baked In

Now, let’s look at a language where the distinction is impossible to ignore. Manam, an Oceanic language spoken in Papua New Guinea, provides a textbook example. In Manam, verb conjugation is fundamentally split along the realis/irrealis line. The verb’s very first prefix tells you which world you’re in.

Verbs in the realis mood (for past and present events) take a subject prefix starting with i- or u-. Verbs in the irrealis mood (for futures, hypotheticals, etc.) take a prefix starting with m-.

Consider the verb ‘to go’ (-lao):

i-lao = “he/she went” (Realis: It is a fact that he/she went.)

m-an-lao = “he/she will go” or “he/she should go” (Irrealis: It is not a fact yet.)

Imagine speaking a language where every verb forces this choice. To say “he runs”, you use a realis form. But to say “Run!” or “he will run” or “if he runs”, you must switch to the irrealis form. This distinction isn’t an afterthought; it’s the first and most basic piece of information you must encode onto the verb.

This feature is common across Austronesian languages (like Tagalog and Malagasy) and many Native American languages (like the Salishan and Uto-Aztecan families), each with its own unique way of marking the divide.

Why This Grammar Matters

The realis/irrealis distinction is more than just a quirky grammatical feature. It’s a window into how a language forces its speakers to frame their experience of the world.

When your language demands you mark every verb for its factuality, you are constantly engaged in an act of epistemic evaluation. You are not just reporting an event; you are simultaneously reporting your commitment to its truth. It builds a fundamental categorization scheme for reality directly into the pipeline of thought-to-speech.

Does this mean speakers of Manam think about reality differently than speakers of English? Not necessarily in a deterministic way. But it does mean that the grammar of their language makes the line between “is” and “could be” exceptionally clear and perpetually relevant in every conversation.

So, the next time you find yourself daydreaming, making plans, or giving an order, take a moment to appreciate the complex grammatical dance you’re performing. You are stepping out of the real and into the vast, creative, and potential-filled world of the irrealis. For some, it’s a choice made with a modal verb or a shift in tone; for others, it’s the very first switch they have to flip to speak at all.