This Inversion is possible?

TasmanTigerIn this case, this below sentence is grammatical?
The race of mankind would perish did they cease to aid each other.
= The race of mankind would perish if they ceased to aid each other.

Yes, but of course it's rare these days, and would hardly ever be used in conversation.

Oh, I got it.

Another question occures to me:

Can you tell me why this kind of inversion occurs?

The race of mankind would perish did they cease to aid each other.
= The race of mankind would perish if they ceased to aid each other.[/

The reason can't be 'the economy of speech' because the sentence didn't get shortened, i think.

Is

Do you have the paragraph whence this came?

An author frequently inverts a sentence to avoid a "sing-song" repetitious pattern.

An author frequently inverts a sentence to avoid a "sing-song" repetitious pattern.

Can you explain 'sing-song' in detail?

I can't understand what 'sing-song' means.

Thanks!

TasmanTigerThe race of mankind would perish did they cease to aid each other.
= The race of mankind would perish if they ceased to aid each other.

The first sentence is completely foreign to me. (The race of mankind would perish did they cease to aid each other.)

In the past, these two versions are possible:

The race of mankind would h

TasmanTigerI can't understand what 'sing-song' means.

Sometimes when you keep repeating the same sentence order (S,V,O; S,V,O; S,V,O) It sounds a bit juvenile, especially in a narrative.
Mary turned off the alarm. She ate breakfast. Then she brushed her teeth. She missed the bus.
Then the dog followed her to school.

We can i

Thank you for your explanation, Avangi!

I got what you mean.

Gooday!

AlpheccaStarsThe first sentence is completely foreign to me. (The race of mankind would perish did they cease to aid each other.)

I agree it's uncommon and certainly dated, but it's correct to my ear:

What Rhygyvarch will have to say will be drawn from written sources.