Diyelim ki yağmur yağdı; evde kalırız.

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:

• Diyelim ki ... = Suppose that ...
• ... evde kalırız. = ... we stay home / we would stay home.

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

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

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

• diyelim = let us say

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

• suppose
• let’s assume
• say that

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

Ki links the introductory phrase to the clause that follows.

In diyelim ki yağmur yağdı, the ki is like that in English:

• Let’s say that it rained
• Suppose that it rained

In everyday English, that is often omitted, but in Turkish ki is very common in this pattern.

So:

• diyelim = let’s say
• ki = that
• diyelim ki = let’s say that / suppose that

Yes, yağdı literally means it rained.

Here:

• yağmur yağdı = it rained / more literally rain fell

A learner may expect something like yağarsa (if it rains) instead. But with diyelim ki, Turkish can present a hypothetical situation as a completed event:

• Diyelim ki yağmur yağdı = Suppose it rained / suppose it has rained

Then the second part gives the reaction or consequence:

• evde kalırız = we stay home / we would stay home

So the past tense here does not necessarily mean the speaker is talking about a real past event. It can be used inside a hypothetical setup.

Because diyelim ki itself is already creating the hypothetical frame.

In English, we often use if:

• If it rains, we’ll stay home.

But Turkish can also use a different structure:

• Diyelim ki yağmur yağdı; evde kalırız.
• literally: Let’s say it rained; we stay home.

So the sentence is not built with the normal Turkish if suffix. Instead, it works more like:

• Suppose rain happened; then we stay home.

A more direct if version would be:

• Yağmur yağarsa evde kalırız.
• If it rains, we stay home / we’ll stay home.

Kalırız is the aorist form of kalmak (to stay / remain):

• kal-ır-ız = we stay

The Turkish aorist often expresses:

• general results
• habitual actions
• predictable consequences
• what normally happens in such a situation

So here evde kalırız means something like:

• we stay home
• we would stay home
• we’ll stay home (depending on context)

Turkish often uses the aorist where English might use will or would.

If you said kalacağız, that would be more explicitly future:

• we will stay

But kalırız sounds very natural for a consequence of a hypothetical or assumed situation.

It is the aorist tense/aspect, which does not match one single English tense exactly.

Depending on context, it can mean:

• we stay
• we do stay
• we will stay
• we would stay

In this sentence, the best feel is a general or expected result:

• Suppose it rains / it has rained; we stay home / we’d stay home.

So it is better to think of kalırız as expressing a regular or natural outcome, not just simple present time.

Evde means at home or in the house.

It comes from:

• ev = house / home
• -de = the locative suffix, meaning in / at / on

So:

• evde = at home

This suffix changes according to vowel harmony and consonant voicing, so you may also see:

• okulda = at school
• arabada = in the car
• şehirde = in the city

Yes, word-for-word it can look strange to an English speaker.

In Turkish, the natural expression for it rained is:

• yağmur yağdı
• literally something like rain fell

This is completely normal Turkish.

Turkish often uses a noun plus a verb where English uses just one verb or a dummy subject:

• yağmur yağıyor = it is raining
• kar yağıyor = it is snowing

Turkish does not need an English-style dummy subject like it here.

Yes, Turkish word order is flexible, but the neutral order here is natural:

• Diyelim ki yağmur yağdı; evde kalırız.

The important point is that the result clause ends with the verb:

• evde kalırız

You could move parts around for emphasis, but that changes the focus. For example:

• Diyelim ki yağmur yağdı; kalırız evde.

This is possible, but it sounds more marked or emphatic than the neutral version. For learners, the given order is the safest and most natural one.

The semicolon separates the hypothetical setup from the result:

• Diyelim ki yağmur yağdı = the imagined situation
• evde kalırız = the consequence

In actual everyday writing, you might also see:

• a comma
• a dash
• or just a pause in speech

So the semicolon is mainly punctuation to show the relationship clearly. It is not a special grammar rule tied only to this expression.

Not usually. The most straightforward and common way would be:

• Yağmur yağarsa, evde kalırız.
• If it rains, we stay home / we’ll stay home.

The sentence with diyelim ki is more like:

• Suppose it rains / suppose it has rained; we stay home.
• Let’s say it rains; we stay home.

So diyelim ki is very useful, but it has a slightly different feel from a plain if sentence. It sounds more like the speaker is asking the listener to imagine or assume a case.

Yes, often you can.

• diyelim ki = let’s say / suppose
• farz edelim ki = let’s assume that

Both introduce a hypothetical situation. However:

• diyelim ki is very common and conversational
• farz edelim ki can sound a little more formal or deliberate

So:

• Diyelim ki yağmur yağdı; evde kalırız.
• Farz edelim ki yağmur yağdı; evde kalırız.

Both are understandable, but diyelim ki is often the more everyday choice.