Listen to real casual Japanese and you will hear particles vanish everywhere: 今日、映画見た？ ("watch a movie today?") with no を, ご飯食べた？ with no を, これ、いくら？ with no が. Learners notice this and draw the natural but wrong conclusion — that particles are optional padding you can shed to sound casual. So they start dropping all of them, and produce sentences like ×友達映画見た that are not casual but simply broken. The truth is that only a specific set of particles drops, and there is a clean reason why. This page is about telling the droppable ones from the load-bearing ones.
❌ 友達映画見た。
Broken, not casual — と is missing, so 友達 has no role. 'With a friend'? 'A friend and I'? The listener can't rebuild it.
✅ 友達と映画見た。
tomodachi to eiga mita
I watched a movie with a friend.
The rule: a particle drops only if its role is recoverable
Here is the principle that sorts them. A particle may drop only when the listener can rebuild its role without it. は, が, and を mark the topic, subject, and object — roles that word order and the verb already point to, so dropping them loses nothing the listener can't reconstruct. But で, と, から, まで mark relations — means, company, source, endpoint — that nothing else in the sentence recovers. Drop those and the role evaporates.
| Particle | Marks | Casual drop? |
|---|---|---|
| は / が / を | topic / subject / object | Yes — role recoverable |
| で | place of action, means, material | No |
| と | with (companion), and, reciprocal | No |
| から / まで | from (source) / to (endpoint) | No |
| より | than (comparison) | No |
| に / へ (destination) | goal of motion | Gradient — see below |
The load-bearing particles: で, と, から, まで
で — place of action or means. Without it, the noun has no anchor.
レストランで晩ご飯を食べた。
resutoran de bangohan o tabeta
I had dinner at a restaurant.
箸で食べるの、上手だね。
hashi de taberu no, jōzu da ne
You're good at eating with chopsticks.
Drop the で from レストラン and the listener can't tell whether you ate a restaurant, ate toward one, or ate at one. The を on the object can go casually (レストランで晩ご飯食べた is fine); the で cannot. The full range of で is on the で: means and instrument page.
と — with, and, reciprocal. This is the one where dropping the particle can flip the meaning outright:
彼女と結婚した。
kanojo to kekkon shita
I married her.
Drop the と and 彼女結婚した means "she got married" — a completely different sentence. と is the difference between you marrying her and her marrying someone. Nothing else in the sentence can recover that, so it stays.
から and まで — source and endpoint. These are unrecoverable by design, because a bare noun could be either end of the range:
駅から歩いて来た。
eki kara aruite kita
I walked here from the station.
駅まで歩こう。
eki made arukō
Let's walk to the station.
駅＿歩く gives you no way to know whether the station is where you started (から) or where you're heading (まで). The particle is the information. (See から and まで: from … until.)
The honest exception: に and へ are gradient
Textbooks like to say destination に "can never drop," but real casual speech tells a subtler story — and it confirms the rule beautifully. Because a motion verb like 行く already implies a goal, the destination's role is partly recoverable, so very casual speech does drop に with 行く/来る:
ねえ、今日どこ行く？
nē, kyō doko iku
Hey, where are we going today?
海行きたい！
umi ikitai
I want to go to the beach!
This is genuinely natural casual Japanese. But notice it only works when the verb guarantees a destination reading. The moment に marks something a motion verb doesn't imply — a recipient (田中さんに言う, "tell Tanaka"), an existence location (机の上にある, "is on the desk"), a specific time you want pinned — dropping it breaks the sentence. So the safe learner rule is: keep に unless you're being deliberately casual with 行く/来る. For the direction nuance between に and へ, see に vs へ.
The other direction: over-marking sounds stiff, not broken
Learners who do master particles sometimes swing the other way and keep every は・が・を in relaxed conversation, which isn't wrong — it just sounds textbook-formal where a native would relax.
ご飯、食べた？
gohan, tabeta
Have you eaten? (casual — を dropped)
ご飯を食べましたか。
gohan o tabemashita ka
Have you eaten? (polite/full — を kept)
Both are correct; they are just (casual) versus (formal). The mistake is only a register mismatch — and it runs the other way too: in writing or formal speech you must keep を・は・が. Dropping them in a report or a business email reads as sloppy, not friendly.
Common mistakes
Mistake 1 — Dropping で (place of action). The location of an action needs で.
❌ 公園遊んだ。
Broken — with no で, 公園 has no role. Where did the playing happen? で anchors it.
✅ 公園で遊んだ。
kōen de asonda
I played in the park.
Mistake 2 — Dropping で (means). "By train," "with chopsticks," "in Japanese" all need で.
❌ 電車来た。
Broken — 電車で来た means 'came by train'; without で it isn't a means at all.
✅ 電車で来た。
densha de kita
I came by train.
Mistake 3 — Dropping と (companion/reciprocal). Without と the person's relationship to the action is lost — and the meaning can flip.
❌ 部長話した。
Ambiguous/broken — 'the department head spoke'? To mean 'I spoke WITH the department head', you need と.
✅ 部長と話した。
buchō to hanashita
I spoke with the department head.
Mistake 4 — Dropping から / まで. Source and endpoint are never recoverable from a bare noun.
❌ 会社電話する。
Broken — is it 'call the company' or 'call from the company'? から makes it 'from the company'.
✅ 会社から電話する。
kaisha kara denwa suru
I'll call from the office.
Mistake 5 — Dropping を in formal writing. Particle-dropping is a casual-speech license; formal registers keep を.
❌ 報告書、提出しました。（社内メールで）
Too casual for a business email — in formal writing, keep the を: 報告書を提出しました.
✅ 報告書を提出しました。
hōkokusho o teishutsu shimashita
I have submitted the report. (formal)
Key takeaways
- A particle drops only when its role is recoverable — which is why は・が・を drop but relational particles don't.
- で, と, から, まで, より stay put: they mark WHERE, HOW, WITH WHOM, and FROM/TO WHERE — relations word order can't rebuild.
- に is gradient: droppable with 行く/来る in very casual speech (the verb implies the goal), but kept for recipients, locations, and formal registers.
- Dropping と can flip the meaning (彼女と結婚した "I married her" vs 彼女結婚した "she got married").
- Over-marking isn't broken, just (formal); and in writing you must keep を・は・が.
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Start learning Japanese→Related Topics
- Particles (助詞): How Japanese Marks GrammarN5 — The big-picture introduction to Japanese particles — short unstressed postpositions that follow a word to mark its role (topic, subject, object, direction), doing the grammatical work English does with word order and prepositions.
- を: The Direct Object MarkerN5 — How を (written with its own dedicated kana, typed 'wo', read o) marks the direct object of a transitive verb — and why the transitive/intransitive split decides whether を appears at all.
- に: Direction, Goal, and RecipientN5 — に marks the endpoint of motion (東京に行く), the recipient of a transfer (母に手紙を書く), and the target of an action — three uses unified by one idea: に is where the action arrives.
- で: Means, Instrument, and MaterialN5 — How で marks the means, instrument, method, and material of an action (電車で行く, 箸で食べる, 日本語で話す) — one particle for what English splits across by, with, and in.
- Confusing は and がN4 — The number-one particle error: defaulting to は for every 'subject' because English marks the subject by position — when the real question is whether the information is already shared (は) or new (が).