[Lingtyp] Languages with only one complementiser

[Jeanne Lecavelier des Etangs-Levallois]

Dear all,

I am looking for languages which have only one complementiser for clausal 
embedding (with no further marking to distinguish between declarative 
clauses and polar questions).
For instance, Akan uses the complementiser 's3' for both declarative clauses 
(e.g. "THAT it is raining" in (1)) and interrogative clauses (e.g. "WHETHER 
it is raining" in (2)), see below. The interpretation depends on the 
predicate (gye di 'believe' in (1), bisaa 'asked' in (2)).

(1) Yaw [gye di] s3 nsuo reto.
Yaw believes COMP rain is.falling
'Yaw believes THAT it is raining.'

(2) Yaw bisaa me s3 nsuo reto.
Yaw asked me COMP rain is.falling
'Yaw asked me WHETHER it is raining.'

Interestingly, even though Akan nim 'know' can take both declarative and 
interrogative complements, it interprets s3-clauses (without further 
markings) as exclusively declaratives, see (3).

(3) Yaw nim s3 nsuo reto.
Yaw knows COMP rain is.falling
'Yaw knows THAT it is raining.' (not: 'Yaw knows WHETHER it is raining.')

If you know of any other language that behaves like Akan for (1) and (2) 
(i.e., one complementiser for both polar questions and declaratives), could 
you please let me know?
And, optionally: could you tell me what interpretation arises under 'know', 
if you know it? (are both possible, or is there only one possible reading?)

  Many thanks in advance!

  Best,
  Jeanne