Four everyday そう patterns do different jobs

そう can point back to a shared idea, or it can attach to another word to mark hearsay or appearance. The practical question is not “What does そう mean by itself?” Ask what comes immediately before and after it.

When そう stands as the content of そうする, it means “do that” or “do it that way.” In a response such as はい、そうです, the same pointing word confirms that the other person's statement is so. After a complete plain clause, as in 九時(くじ)に始(はじ)まるそうです, it reports information you heard or read. After a verb or adjective stem, as in 始(はじ)まりそうです or おいしそうです, it presents an appearance, an immediate impression, or a likely event.

The difference between 始(はじ)まるそうです and 始(はじ)まりそうです is only one syllable on the page, but the evidence changes. The first reports “I hear it starts.” The second judges “It looks likely to start.” Keep that source-of-information contrast at the center and the four patterns stay connected rather than becoming a list to memorize.

Point back to an action or idea

Kotobank defines stand-alone そう as “in that way” and records its use for agreement. This is the そう in everyday phrases such as そうする, そう思(おも)う, and そう言(い)う. It points to content already supplied by the situation or the other speaker.

If a friend proposes taking an earlier train, そうしよう means “let's do that.” You do not need to repeat the whole plan. If you share an opinion, 私(わたし)もそう思(おも)います means “I think so too.” Here そう is not an appearance marker and does not mean that you heard a report.

A short response works the same way. はい、そうです confirms the statement or identification just offered. そうですか is different: it commonly receives new information with “I see” or “is that so?” Depending on voice and context, it may show interest, surprise, or simply acknowledgment. Do not assume that every そうですか expresses strong surprise.

Report information with a complete clause plus そうです

Hearsay そうです follows the plain form of a complete statement. The Japan Foundation describes it as a way to pass on information obtained by hearing or reading, and notes that a source can be named with によると or の話(はなし)では.

With a verb, keep the dictionary form: 始(はじ)まるそうです, “I hear it starts.” With an i-adjective, keep the い: 安(やす)いそうです, “I hear it is inexpensive.” A noun or na-adjective keeps だ: 人気(にんき)だそうです, “I hear it is popular,” and にぎやかだそうです, “I hear it is lively.” These forms preserve the reported statement before adding そうです.

Judge an appearance with a stem plus そうです

Appearance そうです attaches more tightly. JMdict records this auxiliary after a verb's masu-stem or an adjective stem. The Japan Foundation explains that adjective forms describe an impression from how something looks, while verb forms can describe something about to happen or judged likely from the present situation.

For an i-adjective, remove the final い: おいしい → おいしそうです. For a verb, use the masu-stem: 降(ふ)ります → 降(ふ)りそうです. The common adjective いい becomes よさそうです, not いいそうです, when you mean “looks good.” Be careful, because いいそうです can instead be parsed as hearsay: “I hear it is good.”

A Saturday morning market

Mika and Ren are arranging a visit to a neighborhood morning market. Ren suggests meeting before the stalls become busy.

The proposal supplies the content of そう. Mika accepts that plan without repeating 駅(えき)で八時半(はちじはん)に会(あ)う. Casual うん、そうしよう fits between friends; a more polite response could be はい、そうしましょう.

At the market, Mika sees a blue tent beside the entrance and checks whether it is the place to collect their tickets.

This response confirms the identification in the question. It is not the hearsay suffix. The sentence would still make sense if the answer repeated the noun: はい、青(あお)いテントが受付(うけつけ)です. Using そう avoids that repetition.

Ren checked the market's official website before leaving and passes on its schedule.

The complete clause 朝市(あさいち)は九時(くじ)に始(はじ)まる is the reported information. The explicit source 公式(こうしき)サイトによると makes the hearsay job easy to see. Ren is not looking at the stalls and predicting that they will open.

They pass a bakery stall. Steam is rising from a tray that has just come out of the oven.

Here おいしい loses its final い before appearance そう. Mika is reacting to the bread in front of her. She is not quoting someone's review. In ordinary conversation, おいしそう is a useful response to the look, smell, or presentation of food, but it does not claim that the speaker has tasted it.

A few minutes later, black clouds spread across the western sky and the wind picks up.

The verb changes from 降(ふ)ります to its stem 降(ふ)り before そうです. The black clouds are present evidence for Mika's prediction. Compare 天気予報(てんきよほう)によると、雨(あめ)が降(ふ)るそうです, which would report the forecast instead.

Ren suggests waiting inside the station if the rain begins.

The story returns to demonstrative そう. The whole proposed action becomes the content of そうしよう. That repetition shows the common thread: stand-alone そう points back, while suffix そう asks you to inspect the form attached before it.

Use a quick source test. Are you pointing back to what someone just proposed? Use そうする or another stand-alone form. Are you confirming their statement? はい、そうです may fit. Are you passing on something heard or read? Preserve the complete plain clause before hearsay そうです. Are you judging from what is visible or happening now? Attach appearance そうです to the appropriate stem.