These judgements are usually about relationships between concepts or between concepts and reality.
Assertions are always either true or false.
In believing something one asserts an assertion at least to oneself. The positions we hold on various topics are assertions. If we are to think critically about our beliefs and the positions of those around us on any topic, then, we must pay careful attention to what is really being asserted. We use declarative sentences to communicate or stand for assertions. The actual physical marks or sounds used to represent sentences may be called sentence tokens.