Learn Hardcore Turkish: Diyelim ki yağmur yağdı; evde kalırız. - Suppose it rained; we would stay at home.

Breakdown of Diyelim ki yağmur yağdı; evde kalırız.

What does diyelim ki mean in this sentence?

Diyelim ki is a common way to mean let’s say, suppose, or imagine that.

It introduces a hypothetical situation. So the sentence is setting up a scenario first, and then giving the result:

It is not the ordinary if pattern, but it often works in a similar way in meaning.

Why is it diyelim? Doesn’t that literally mean let’s say?

Yes. Diyelim literally comes from demek (to say) and means let’s say.

Grammatically, it is the 1st person plural imperative / hortative form:

But in real usage, diyelim ki often functions as a fixed expression meaning:

So even though the literal grammar is let us say, the actual meaning is often more like suppose.

What is the role of ki here?