sorry, i can only help you with that when my language and the iphone language are the same

Whose language? Siri?

Have you checked to make sure siri's language is that of your own?

Settings>General>Siri>Language

I've noticed that siri is not good with dialects. If you have a heavy accent or aren't speaking properly, therein may lie the issue.

If you are speaking clear and concise sentences, there is an issue with the software and the device may need to be restored.

You can test to see if there is an issue with the microphone by attempting to create a voice memo and listening to it. If your voice sounds distorted through multiple tests, there is a hardware issue with the iPhone and it may need repaired.

Man, I found the answer. I had the same problem.

Try this:

1. Settings -> General -> Language & Region -> iPhone language -> English (U.S.)

2. Make the first language on "preferred language order" English (U. S. )

3. Settings -> Siri -> language -> English (United States)

4. Setting -> Siri -> Siri voice -> American

That's it:)