Some Languages Make You Say How You Know

In many languages a speaker may indicate their source if they wish. In others the verb will not form until the source of the information has been specified.

The categories that get marked

Systems vary in how many distinctions they draw. A basic one separates what the speaker witnessed from what they did not, and richer ones subdivide further.

Common categories include direct visual evidence, hearing something happen, inferring it from traces, and being told by someone else.

Each has its own marker, and using the wrong one is a grammatical error as well as a social one, since it misstates the basis of the claim.

It is not the same as certainty

Marking a statement as hearsay does not mean the speaker doubts it. It reports the route by which the information arrived, and that route may be entirely reliable.

Conversely a direct marker does not guarantee accuracy. It says the speaker saw the event, which is a claim about the speaker rather than about the world.

Languages that lack these markers blur the two, which is why translations often add hedging that was not present, or drop information that was.

What speakers do with it

The requirement makes it awkward to pass on rumour as fact, because the grammar will show what was done. Speakers must either mark it or lie in a detectable way.

Narrative traditions use the markers deliberately. Stories set in the distant past take a particular marker throughout, and switching it signals a change in the kind of story being told.

Reported speech within a story can carry its own marking, which lets a narrator distinguish what a character witnessed from what a character was told.

Learning the system late

Adult learners find evidentials among the hardest features to acquire, because the choice is obligatory and there is no default to fall back on.

Speakers of languages without the category tend to overuse the direct marker, which sounds like an overclaim to native speakers rather than a grammatical slip.

Children acquire the system early, which suggests the difficulty is not conceptual but a matter of habitually tracking something one has never had to track.

Where it comes from

Evidential markers usually develop out of ordinary verbs and constructions. Verbs meaning see, hear or say are the commonest sources, worn down into affixes over time.

Once grammaticalised they become obligatory, which is the step that separates a language with evidentiality from one that merely has words for reporting.

The process runs the other way too. Markers can weaken into optional particles and then disappear, leaving a language whose older texts distinguish something its speakers no longer do.