Exercises on とする・とすると・とすれば・としたら

Question 1 of 10

彼が犯人だとする。

In the hypothetical use discussed in the article, what does とする primarily do?

It adopts the preceding proposition as a premise within the reasoning, without necessarily asserting it as true in the real world. It indicates how likely the speaker considers the preceding proposition to be. It necessarily turns a false proposition into a possible one. It signals that the speaker has decided to accept the preceding proposition as fact.

Question 2 of 10

参加費を千円とする。

The same sentence can mean either “the participation fee is set at 1,000 yen” or “let us assume a participation fee of 1,000 yen” for the purposes of a calculation. What chiefly determines which interpretation applies?

Whether the subject of する is expressed or left implicit. Whether 千円 is intended as an exact or approximate amount. The context and the purpose of the discourse: the structure may actually establish a value or merely adopt it provisionally within a line of reasoning. The register: in writing とする establishes an actual decision, whereas in speech it is hypothetical.

Question 3 of 10

P とすると・P とすれば・P としたら

Which analysis correctly describes how these three forms are built?

とすると, とすれば, and としたら are three independent particles attached directly to P. In all three forms, P itself is transformed into と, ば, or たら respectively. Only とすると derives from とする; the other two are independent constructions. P is first adopted through とする, and する then takes the conditional form と, ば, or たら respectively.

Question 4 of 10

とすると・とすれば・としたら

Which description best captures their typical pragmatic tendencies?

とすると is used for real situations, とすれば for probable situations, and としたら for unreal ones. とすると readily foregrounds what follows from the premise; とすれば foregrounds the acceptance and evaluation of the premise; としたら is particularly well suited to imagined scenarios, questions, and personal reactions. とすれば is always more formal and is therefore grammatically preferable to the other two. The three forms have exactly the same function and differ only in style.

Question 5 of 10

明日の試験に合格したとする。

How should 合格した be understood in this sentence?

It proves that the exam has already taken place despite the presence of 明日. It is grammatically incompatible with reference to a future event. It indicates that the speaker considers passing the exam highly probable. The exam is still in the future, but within the hypothetical scenario it is represented as already having been passed.

Question 6 of 10

行くとしよう／行こうとする

Why should these two structures not be confused?

としよう is a past form, whereas 行こうとする is a non-past form. Only 行こうとする contains the verb する. としよう necessarily expresses a real decision and can never introduce an assumption. In 行くとしよう, the volitional applies to する and, in the use discussed here, means “let us suppose that we go”; in 行こうとする, the volitional belongs to 行く, and the construction can express an attempt or the imminence of an action.

Question 7 of 10

温度は一定だとする。／温度が一定だとする。／温度を一定とする。

Which analysis correctly distinguishes the roles of は, が, and を in these examples?

は, が, and を perform the same function here and can be freely interchanged. は always marks contrast, が identifies the person making the assumption, and を marks the subject of the hypothesis. は presents 温度 as the topic; が marks it as the subject within the hypothesized situation; を presents it as the element to which a value or property is assigned. が and を are equivalent here, while only は changes the structure of the sentence.

Question 8 of 10

雨が降ったら、試合を中止します。／雨が降るとしたら、夕方以降だろう。

What is the fundamental structural difference between these two sentences?

In the second sentence, としたら indicates that rain is considered less likely. The first refers to the future, whereas the second necessarily refers to the past. In the first, たら directly links the event to its consequence; in the second, the possibility of rain is first adopted as a premise and the reasoning then proceeds within that scenario. In the second sentence, としたら is simply a more formal version of たら.

Question 9 of 10

彼はすでに辞退したらしい。とすれば、次の候補は田中さんだ。

What role does とすれば play in this example?

It introduces an entirely new hypothesis unrelated to the preceding sentence. It signals that the speaker considers the information just received to be false. It turns 次の候補は田中さんだ into the premise of the reasoning. It picks up the preceding information as a premise and introduces an inference drawn from it.

Question 10 of 10

とする・とすると・とすれば・としたら

Which statement about register is the most accurate?

Register preferences exist, but they interact with discourse function: としたら has a strong affinity with conversation and imagined scenarios, とすれば with measured analytical reasoning, and とすると with drawing out the consequences of a premise, without any of them being rigidly restricted to either writing or speech. としたら belongs exclusively to informal speech and cannot be used in a polite question. とすれば is always written and formal, whereas とすると is exclusively conversational. The choice among the four forms depends only on the degree of politeness required.