すると links an action to what follows

すると appears in two structures that look alike but do different jobs. At the beginning of a new sentence, it is a conjunction meaning “then,” “thereupon,” or “in that case.” Attached directly to a plain nonpast verb as V-ると, it means “when doing V leads to...” or “whenever V happens, the following result occurs.”

Learn the punctuation and sentence shape before translating. In 受付(うけつけ)が終(お)わりました。すると、先生(せんせい)が出(で)てきました, the first sentence is already complete. The separate すると moves the story to what happened next. In ボタンを押(お)すと、整理券(せいりけん)が出(で)ます, と is attached to 押(お)す inside one sentence and presents pressing the button as the trigger for the result.

Sentence-initial すると: then, as a result, or in that case

The conjunction すると looks back at the preceding statement. Kotobank records three closely related movements: a later event simply follows, the earlier event leads to a result, or the speaker draws a conclusion from the information just given. The first two are useful in stories and explanations. Importantly, the sequence does not always claim a necessary cause. “This happened. Then that happened” can be enough.

The inference use is especially useful in dialogue. If someone gives you a schedule, price, rule, or other fact, you can begin your response with すると and state what that fact seems to mean: すると、今(いま)からでは間(ま)に合(あ)わないということですか, “Then does that mean I cannot make it in time if I leave now?” The speaker is not describing a physical event. They are checking the conclusion they drew.

V-ると: a trigger and its result

In V-ると, attach と to the verb's plain nonpast form: 押(お)すと, 着(つ)くと, 乾(かわ)くと. Tokyo University of Foreign Studies explains that this pattern commonly presents a relationship that holds repeatedly or normally. It works well for natural changes, habits, and machine operations: when the trigger occurs, the result ordinarily follows.

The same source also records a discovery use. The speaker performs or reaches the first action and then encounters the situation in the second part. In 会場(かいじょう)に着(つ)くと、入口(いりぐち)に列(れつ)ができていました, “When I arrived at the venue, there was a line at the entrance,” arriving creates the point from which the speaker discovers the line. Even though the discovery belongs to a past story, 着(つ)く remains in the plain nonpast form before と.

The second part matters. The basic V-ると pattern presents a result rather than the speaker's request, invitation, or one-time plan. For “When you arrive, please call me,” use 着(つ)いたら、電話(でんわ)してください. Japan Foundation teaching material directly contrasts と with たら and marks たら for an intentional expression such as a request after arriving.

Arriving for a pottery workshop

Aya is going to a weekend pottery workshop at a community center. It is her first visit, and she expects to check in quickly. When she reaches the building, she discovers that many people arrived before her.

This is V-ると with discovery. Aya's arrival is the first event; the line is what she finds there. The sentence does not say that her arrival caused the line.

Aya reaches the desk and gives the receptionist her name. The check-in finishes. At that moment, the instructor appears from a room behind the desk.

Here すると begins a new sentence. It advances the story from one completed event to the next. The instructor may have been waiting for check-in to finish, but the grammar does not force a claim that the first event mechanically caused the second.

The receptionist then explains the numbered-ticket machine used when several people are waiting.

This V-ると sentence describes how the machine normally works. Pressing the button is the repeatable trigger, and the ticket is the automatic result. It is different from narrating one completed press with 押(お)しました。すると....

Aya notices that a friend who lives nearby might enjoy the workshop. She asks whether a reservation is required.

The second speaker uses sentence-initial すると to check an inference. Aya takes the rule she has just heard and draws a possible conclusion about her friend. The ending んですね makes the response sound like confirmation of a newly understood implication.

Inside the classroom, the instructor explains what happens to the clay after students shape it.

This is another regular relationship. The change in color ordinarily follows drying, so V-ると fits naturally. It is not a request and not merely one surprising event in today's story.

Aya sends her friend the address. Because the friend has never visited the center, Aya asks for a message after arrival.

The request 連絡(れんらく)してください is the speaker's desired action, not an automatic result. 着(つ)いたら is the practical choice. Compare it with 教室(きょうしつ)に着(つ)くと、先生(せんせい)がいました, which would report discovering that the instructor was there.

A quick reading test keeps the structures separate. If you can place a full stop before すると and it means “then” or “in that case,” it is the conjunction. If と is attached to a verb and the first action triggers a regular result or leads to a discovery, it is V-ると. If you are telling someone what to do after a future event, check whether たら is the natural choice instead.