(19) Does the language have the 'wh-scope marking' construction?
a) Plain example
Context: The police is investigating in a criminal case.
*What does the detective think [who the criminal killed yesterday]?
Intended: 'Who does the detective think, that the criminal killed yesterday?'
Explanation: Working definition of 'wh-scope marking': A dummy interrogative (often 'what' but also 'how' etc.) can be used in the matrix clause to question a constituent from an embedded clause. Make sure that the embedded interrogative is morphologically distinct from the possible dummy element. This is not grammatical in English, but, e.g., is in Hindi:
Siitaa-ne kyaa socaa [ki ravii-ne kisko dekhaa?]
Sita-ERG what thought [that Ravi-ERG who saw]
'Who did Sita think that Ravi saw?'
Note: 'What did Sita think? Who did Ravi see?' (Fanselow)
Background: Wh-scope marking constructions seem to be restricted to O-V languages.