In this vocabulary and usage question, complete the sentence “A police detective often finds himself in the position of having to __________ between a lie and a truth” by choosing the verb that correctly describes the act of telling the difference between two things.

Introduction / Context:
This question assesses your knowledge of vocabulary related to reasoning and judgement. The sentence describes the work of a police detective, who must decide whether a statement is a lie or the truth. The blank requires a verb that expresses the idea of telling the difference between two possibilities. Such questions test both word meaning and the ability to recognise collocations like “distinguish between X and Y.”

Given Data / Assumptions:

• The sentence is: “A police detective often finds himself in the position of having to __________ between a lie and a truth.”
• Options: extinguish, distinguish, finish, languish.
• The detective is not literally destroying, completing, or wasting away; he is making a careful judgement between two alternatives.
• The standard phrase in English is “to distinguish between A and B.”

Concept / Approach:
The core concept is understanding the meaning of “distinguish,” which means to recognise or show the difference between two or more things. The context clearly involves deciding whether something is false or true, which is an act of discrimination or differentiation. The other verbs have unrelated meanings: “extinguish” means to put out or destroy (as in a fire), “finish” means to complete, and “languish” means to become weak or suffer from being forced to remain in an unpleasant situation. Therefore, only “distinguish” is semantically and collocationally appropriate.

Step-by-Step Solution:
Step 1: Identify what the detective is doing: he is comparing statements to figure out which is a lie and which is the truth.Step 2: Recall that the usual expression is “to distinguish between a lie and the truth.”Step 3: Consider option B, “distinguish,” which precisely means to tell apart or recognise differences.Step 4: Check option A, “extinguish,” which means to put out something like a fire, and clearly does not fit here.Step 5: Check option C, “finish,” meaning to complete, which does not match the context of comparing truth and lies.Step 6: Check option D, “languish,” which means to become weak or suffer, and is entirely unsuitable.Step 7: Conclude that “distinguish” is the only correct choice.

Verification / Alternative check:
Insert “distinguish” into the sentence: “A police detective often finds himself in the position of having to distinguish between a lie and a truth.” This is a natural and meaningful statement. If we try the others, we get absurd results such as “having to extinguish between a lie and a truth,” which is grammatically and semantically wrong. Similarly, “finish between a lie and a truth” and “languish between a lie and a truth” do not convey any sensible meaning. This confirms our choice.

Why Other Options Are Wrong:
“Extinguish” is used for putting out fires, lights, or sometimes hopes, but not for comparing statements. “Finish” refers to bringing something to an end, rather than assessing its truthfulness. “Languish” means to become weak or suffer from neglect; it does not involve judging or comparing information. None of these verbs collocates with “between a lie and a truth” in standard English usage.

Common Pitfalls:
Some learners may confuse “distinguish” with “extinguish” because the words look similar, especially under time pressure. Others might not know the meaning of “languish” and therefore hesitate between unfamiliar options. To avoid such issues, it is important to build a strong vocabulary foundation and to memorise common word combinations like “distinguish between,” “differentiate between,” and “tell the difference between.” Recognising these formulaic expressions can significantly speed up problem solving in vocabulary questions.

Final Answer:
The correct verb to complete the sentence is distinguish, giving “having to distinguish between a lie and a truth.”