I got it to work.
Now before I tell you how I did it let me say that I got it to work om my machine. I do not garantee that it will work on your machine.
In other words; I do not claim that my ‘solution’ is universal or that it will work for you.
My info:I live in the Netherlands and I want Yosemite to use the English language and still get online results with a Spotlight search
.This is what I did to make it work.
I went to ‘Preferences’ --> ‘Language & Region --> ‘Preferred Language: English’ --> ‘Region: United States (Custom)
Then I clicked on Time Format to choose ’24-Hour Time’.
So now I got the English language, the United States (Custom) region and the European time system.
Then I clicked on ‘Advanced’ in the lower right corner
This took me to the ‘Advanced’ screen.
I have set the following preferences:
Format Language: English. (This MUST be set to English if you want online results in Spotlight)
Number separators: Grouping: Nothing changed
Currency: Euro
Measurement units: Metric
Then I clicked the lower right ‘OK” button.
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So here are my thoughts.
You can choose English as language and the United States as Region and then in the advanced screen customize the setting to your particular situation depending on the country that you are in.
Again; I don’t guarantee that it will help everyone. I hope it will help you.