Logical ReasoningDifficulty: Medium

PT9 S2 Q21 Explanation

English and the Austronesian language

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsNecessary Assumption

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Stimulus

English and the Austronesian language Mbarbaram both use the word “dog” for canines. These two languages are unrelated, and since speakers of the two languages only came in contact with one another long after the word “dog”was first used in this way in either language, neither language could have borrowed the word and meaning the similarity is due neither to language relatedness nor to borrowing.

What this question is testing

Necessary Assumption

Your task

Find the assumption the argument requires in order for its conclusion to hold.

Common trap

Answers that would help the argument but aren't strictly required (sufficient, not necessary).

Winning move

Negate each choice — the right one breaks the argument when negated.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
21.

The argument requires that which one of the following

Answer choices

  1. Too Strong: no other words5% picked this

    English and Mbarbaram share no words other

    The argument never worries about whether they share other words, so this is unnecessary. If they did share other words, it wouldn’t weaken the conclusion. Just because "dog" is the only shared word mentioned, doesn't mean the author is saying that "dog" is the only shared word.

  2. Opposite (if anything)2% picked this

    Several languages besides English and Mbarbaram use “dog” as the word

    If anything, this answer would weaken the argument, because the more languages that use "dog", the more likely we could explain the English / Mbarbaram similarity by saying they're both borrowing from one of these other languages.

  3. Too Strong: usually9% picked this

    Usually when two languages share a word, those languages are related

    The concept of "most / usually / typically / generally" is famously wrong on Necessary Assumption 98% of the time. Who cares whether shared words are due to related languages 49% of the time vs. 51% of the time? That higher number isn't necessary to this argument.

  4. Correct78% picked this

    There is no third language from which both English and Mbarbaram borrowed

    Why this is right

    This has a lovable Defender ruling-out "no". If we negate this answer, does it weaken the argument? Yes, if there IS a third language from which English and Mbarbaram borrowed "dog", then dog is a case where languages share a word due to borrowing. But the argument hinged on "dog" being an example of a similar word that had nothing to do with language relatedness and nothing to do with borrowing.

    Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.

  5. Too Strong: must6% picked this

    If two unrelated languages share a word, speakers of those two languages must have come in contact with

    We separately know that English and Mbarbaram are unrelated languages, share a word, and have come into contact with each other. But the argument never assigned any permanent connections between these concepts. If we hear, "Lisa is a poet and grew up in Kansas", that doesn't allow us to say "If someone grew up in Kansas, they must be a poet".

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