Aspects in Japanese
Aspect in Japanese — what it is, how it differs from English and Polish, and why knowing verb types matters for using ている and る correctly.
Tense, aspect, and mood — a quick orientation
These three categories often get conflated, but they do different things.
Tense locates an action in time — past, present, future. Not every language grammatically marks all three; some don't have a distinct future tense at all.
Aspect describes how an action unfolds within a time frame — whether it's completed, ongoing, habitual, or repeated. Aspect is the grammar of phases: did the action finish? Is it still happening? Does it recur?
Mood (or modality) indicates the speaker's stance toward the action — whether something is real, probable, possible, obligatory, and so on.
The first definition of aspect in Merriam-Webster is: "a particular status or phase in which something appears or may be regarded." The key word is phase.
Every action has a beginning and an end — if that end has been reached, the aspect is perfective (completed). If the action is still in progress or hasn't concluded, the aspect is imperfective (ongoing). Some actions are viewed from the angle of regularity — they repeat, they're habitual, they're expected to continue. Aspect is what lets you specify not just when something happened, but what phase it was in.
How many aspects does each language have?
English has four aspectual distinctions:
I go to school — simple (habitual; regular action) I'm going to school — continuous (ongoing; happening now) I have gone to school — perfect (completed; result relevant now) I have been going to school — perfect continuous (ongoing process with present relevance)
Polish has two aspects — perfective and imperfective — built directly into the verb form. Japanese also has two, expressed through る and ている.
Aspect in Japanese — る and ている
Japanese encodes aspect in the verb ending:
る (plain form) — perfective aspect: the action is viewed as a complete unit, with a defined beginning and end
ている — imperfective aspect: the action is ongoing, incomplete, or the result of a completed action is still in effect
With only two aspects to work with, ている does a lot of heavy lifting. Japanese compensates with other grammar points that add nuance — but the core aspectual distinction runs through this single pair.
For a detailed breakdown of ている and how it interacts with verb types: this post.
Why intuition from English or Polish fails in Japanese
Consider the verb 行く (いく) — "to go."
学校に行く = going to school (perfective; future or habitual) 学校に行っている = has gone to school / is in the state of having gone
In English, "I'm going" suggests an ongoing action — movement in progress. The equivalent-looking form 行っている, however, expresses a resultative state: the person has already arrived. The journey is complete; what ている points to is the resulting condition.
行く is a telic verb — it has a built-in endpoint (arriving at the destination). In Japanese, telic verbs in ている form express the state that holds after that endpoint has been reached, not the action leading up to it.
This is where learners often go wrong. English "I'm going" and Japanese 行っている look structurally parallel — progressive + verb — but they mean different things because English and Japanese aspect don't map onto each other cleanly. The same intuition that works automatically in English produces incorrect Japanese.
Why verb types matter
The only reliable way through this is to understand verb types. Telic vs. atelic, change vs. non-change, transitive vs. intransitive — these distinctions determine what ている will produce for any given verb. There's no shortcut: aspect in Japanese requires a different way of looking at what a verb is doing, not just when it happened.
Polish also has two aspects, but they don't overlap cleanly with Japanese — what counts as imperfective in Polish won't always be imperfective in Japanese. Each language parcels up the same reality differently.
This doesn't mean you need to consciously analyse every verb before using ている. In many cases, English -ing and Japanese ている will line up just fine — and over time, a lot of it becomes intuitive anyway. But knowing the underlying logic helps in a specific way: it explains why a native speaker corrected you, why your Japanese sounded slightly off even though it was technically close, or why a sentence you thought you understood meant something different from what you expected. That kind of understanding compounds. You won't always need to stop and think — but when something doesn't click, you'll know where to look.