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Hi,

Could you tell me which phrase(s) are natural from your standpoint ?

1. Children begin to speak at the age of three
2. Children start to speak at the age of three
3. Children begin speaking at the age of three
4. Children start speaking at the age of three

Thanks a lot!
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They are all okay grammatically, but the infinitive versions (1 and 2) show the process is starting. With the -ing forms, it sounds like they suddently just start talking, as opposed to it being an acquisition.

However, language acquisition starts MUCH earlier than 3.

So maybe you mean they start talking in a way that is more similar to adult speech, with full sentences, and such, which does happen around 3. If that's the case, then modify "speaking" - Children start speaking coherently around the age of 3. I see no different between "start" and "begin."
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MrPernicketyCould you tell me which phrase(s) are natural from your standpoint ?
All four seem very natural to me. start and begin are pretty much synonymous, except you can only start machinery (cause it to start), not begin it.

I started the [car / truck / engine / motor]. (*I began the [car / truck / engine / motor].)

CJ
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Thank you Barbara nand Jim !

I've taken in your lesson !
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