"I don't know if they escaped" / "If they escaped, they're long gone" - Conditional protases and interrogative clauses

Question

English, conditional protases [ read "antecedents" ] bear a close resemblance to interrogative clauses. For example, they are often identical to subordinate closed interrogative clauses:

• If Bertha accepted that offer, she's crazy.
• I don't know if Bertha accepted that offer.

They can be identical to main clause interrogatives:

• Should you see Bob?

• Should you see Bob, tell him to phone me.

• Had she asked them?

• Had she asked them, they'd have been happy to give her the elephant.

They can be very similar to and sometimes the same as main clause or subordinate clause open interrogatives:

• Whoever would agree to that?
• Whoever would agree to that, Bob won't.

Are there any non-European or non-Indo-European languages that use conditional protases that correspond to any or all of the three types of interrogative clauses listed above? I'm extremely interested in all three, but extra-specially interested in protases corresponding to closed interrogatives.

Answer 1

Even though I'm not quite sure about the exact definition of "conditional protases" (or "antecedents"), especially in the first language of my own (Thai), I believe it's safe enough to make these points based on your examples:

• There is nothing in Thai that is equivalent to the use of if in subordinate closed interrogative clauses. Thai has two main words for if, i.e., ถ้า ("tha") and หาก ("hak"). To express the same idea as English I don't know if Bertha accepted that offer in Thai, we would use หรือไม่/หรือเปล่า ("rue-mai"/"rue-plao"), which roughly means or not, e.g., (lit.) I don't know Bertha accepted that offer or not.
• Thai doesn't use inversions like English, so an inversion in a main clause interrogative such as Should you see Bob, tell him to phone me does not exist in Thai. To express the same idea, we always express it with ถ้า (if), e.g., (lit.) If you see Bob, tell him to phone me.

The case of main clause open interrogatives (Whoever would agree to that, Bob won't.) is quite interesting. As a pro-drop language, Thai seems to allow main clause open interrogatives to be used as subordinate closed interrogative clauses almost freely, if not always. This can roughly be categorized into two main groups, i.e., yes-no questions (which works quite like English whether when it's embedded in a subordinate clause), and wh-questions (which works quite like English wh-ever words in subordinate clauses). Here are a couple examples:

• yes-no questions¹:
  Thai: ชอบหรือไม่ชอบ คุณก็ต้องทำ
  Romanization: "chop rue mai chop, khun ko tong tham"
  Literal translation: Like or not like, you must do (it).
  Standard English: Whether you like it or not, you have to do it.
  Gloss: ชอบ-chop=like หรือ-rue=or ไม่-mai=not ชอบ-chop=like คุณ-khun-you ก็-ko=PARTICLE ต้อง-tong=must ทำ-tham=do

• wh-questions²:
  Thai: ใครอยากไป เจไม่อยาก
  Romanization: "khrai yak pai, je mai yak"
  Literal translation: Who wants (to) go, Jay (does) not want.
  Standard English: Whoever wants to go, Jay doesn't want to.
  Gloss: ใคร-khrai=who อยาก-yak=want ไป-pai=go เจ-je=Jay ไม่-mai=not อยาก-yak=want

¹ชอบหรือไม่ชอบ (lit.) Like or not like? is a question. It has basically the same meaning as ชอบหรือไม่/ชอบหรือเปล่า (lit.) Like or not?. After careful consideration (and much thought!), I believe that all alternatives could be used, but the duplication of the verb (e.g., Like or not like) seems to be more common in subordinate clauses that are equivalent to whether-clauses in English. On the other hand, the other alternative (i.e., Like or not) is more common in reported questions where we can use either if or whether in English (e.g., She asked if/whether I like it or not).

²The sense of "ever" is implied. To be explicit about this sense, we could use บ้าง ("bang"), e.g., Who wants to go บ้าง. ใครอยากไป(บ้าง) (lit.) Who wants to go (บ้าง)? is a question. When we have more than one wh-word, we use only a single บ้าง, e.g., ใครจะทำอะไรที่ไหนเมื่อไหร่กับใคร(บ้าง) ผมไม่ทราบ (lit.) Who(ever) do what(ever) where(ever) when(ever) with whom(ever), I don't know.

³All romanized transcriptions follow the Royal Thai General System of Transcription (RTGS).

Answer 2

Conditional sentences in Farsi (Persian) can be classified into two categories, depending on whether they do or not have a conditional word (a conjunction, a fused relative type of thing, etc.).

None of the conditional words (اگر، چنان‌چه، هر گاه، چندان‌که، چون، هر کس، ...) would go in interrogative clauses, as far as my struggles to fit them went.

And the other type of conditionals have a special verb form (التزامی), which, again, don't normally go in interrogative clauses.

But good news is that we can find some special interrogative clauses featuring this type of verb form that can act as conditional clauses too. Here's an example pair:

• clause in bold acting as a conditional:
  "Whether she's here or not I can't see her."
  Translation: ".این‌جا باشد یا نه، نمی‌توانم ببینمش "
  Romanization: "inja bashad ya na, nemitavanam bebinamash."
• the same clause, in bold, acting as an interrogative:
  "I don't know whether she's here or not."
  Translation: ".نمي‌دانم این‌جا باشد یا نه "
  Romanization: "nemidanam inja bashad ya na."

Using this construction, many other example pairs can be made. There might also be other pairs with different constructions.
But please know that these examples do not suggest a general rule that conditional clauses are similar to interrogative clauses in Farsi, because they are usually not similar, and I managed to contrive something only after pondering for a while.

Answer 3

Let's start with subordinate closed interrogative clauses, since I think in Vietnamese, they work pretty much the same way as in English:

• If Bertha accepted that offer, she's crazy.

Translation:

Nếu Bertha đồng ý lời đề nghị đó, cô ấy thật là điên rồ.

Funny thing is, as you can see, you can translate the English sentence above into Vietnamese word-by-word, and the word order still stays the same. Note that I'm not using the particle "đã" (which is sometimes used to indicate past tense) before "đồng ý", since it sounds really awkward in this context (in fact, most of the time, if not almost always we wouldn't use it.)

• I don't know if Bertha accepted that offer.

Translation:

Tôi không biết Bertha có chấp nhận lời đề nghị đó hay không/chưa..

So in Vietnamese, if you put the conditional clause (that is "if Bertha accepted that offer" in this case) behind the main clause (I don't know/I'm not sure/I don't care, etc.), you will need to remove "nếu" (which means "if" in English). And then you have to add "hay không" or "hay chưa" (which is literally translated as "or not" in English) at the end of the sentence, because without them, it would sound really odd and more likely nobody would understand what you mean.

In Vietnamese, there are no inversions used in conditional sentences, so we don't use something like "Should you see Bob, tell him to phone me" and such... like in English. Only "If" works! -> "If you see Bob, tell him to phone me"

Let's move on to main clause open interrogatives!

Whoever would agree to that?

Translation:

Ai mà đồng ý với điều đó?

But to express the idea of "Whoever would agree to that, Bob won't.". You can NOT just copy-paste the translation above and make it like: "Ai mà đồng ý với điều đó, Bob thì không đâu" NO! You should use this instead:

Ai đồng ý thì đồng ý, Bob thì không đâu.

Answer 4

In Modern Hebrew, embedded questions are introduced by im 'if', which also introduces conditional protases. E.g.:

Im hu ba-bayt, daber ito. "If he is at home, speak to him."

Ani lo yodea im hu ba-bayt. "I don't know if he is at home."

That said, Modern Hebrew syntax is very heavily affected by European languages, so it arguably doesn't count as a "non-European language".

The fact that many European languages have this double function of if is, I think, due to areal diffusion rather than inheritance: Latin doesn't have this feature, but its Romance daughters do.

Answer 5

The reason for the grammatical kinship between antecedents and questions is that they play corresponding roles in human reasoning. Questions are the conversational counterparts to antecedents. Compare:

statement: "If John left early, then he didn't see Joyce."  
conversation: "Did John leave early?  Then he didn't see Joyce."  

The two most popular ways of presenting a logical system are the axiomatic method and the natural deduction method. As the name suggests, most people find the natural deduction method easiest to comprehend. In a natural deduction system, suppositions are made, and consequences are drawn from those suppositions, where the suppositions correspond to questions in actual conversations. The system gives a systematic way of going back and forth from the conversational forms of deduction (entailments) to the statement forms (implications).