Complementizer

More on this in the refgram
Syntax: Complementizer phrases

A complementizer is a word that starts a clause, like ꝡa or mä or ꝡë.

In Toaq, main clauses start with a complementizers in , whereas subordinate clauses start with complementizer in . The complementizers are:

Toaq complementizers

Type	Main clause	Subclause	Meaning
Declarative or wh-question	ꝡa	ꝡä	"that"
Yes-no question	ma	mä	"whether"
Degree question	tıo	tïo	"how (much)"
Restrictive relative clause		ꝡë	"which"
Non-restrictive relative clause		jü	"which"
Property / lambda clause		lä	"λ"

Null complementizers

English doesn't really have an equivalent of ꝡa: you can't say something like *That I like this book. in the main clause. But in Toaq, it's perfectly normal to say Ꝡa cho jí ní kue. The word ꝡa acts as a sentence fence.

Conversely, English allows for a "null complementizer" in a subclause: instead of I know that you like this book, you can say I know you like this book. In Toaq, this is not allowed: you must say Dua jí, ꝡä cho súq ní kue. Only the declarative main-clause complementizer ꝡa is optional.