[nludd]

I'm Dutch, so I have to switch languages often as well. I don't think I get what you're trying to explain. Could you provide some examples?

If I search for an English error message, I.. search for that message. If I search for a Dutch person, I look him up on the Dutch Wikipedia if he's well-known enough.

[rtpg]

You're learning Django, and the error messages are in English.

There might be a Dutch programming blog talking about this error message, but they'll never be able to be discovered because any English source will end up on top.

Another example: you are traveling in a foreign country, and don't really know the local language. You Google for information about a restaurant, hoping to land on something Trip Advisor-y. You end up on the local website, that you're completely unfamiliar with.

You want to offer a blog for English-speaking expats in Paris. Your exposure in Google is really low because of the niche audience, and the fact that French sources about places you're talking about will be much more viewed.

[nludd]

>There might be a Dutch programming blog talking about this error message, but they'll never be able to be discovered because any English source will end up on top.

Add "lang:nl".

>Another example: you are traveling in a foreign country, and don't really know the local language. You Google for information about a restaurant, hoping to land on something Trip Advisor-y. You end up on the local website, that you're completely unfamiliar with.

Look up the restaurant on https://www.tripadvisor.com/. Why would you use a general purpose search engine if you already know where to find the right information? Or you could add "lang:en" to your query.

>You want to offer a blog for English-speaking expats in Paris. Your exposure in Google is really low because of the niche audience, and the fact that French sources about places you're talking about will be much more viewed.

Those expats could add "lang:en" to their queries about the places you have blogged about.

I am not denying that there is some value in Google filling in these blanks for you, but 99% of examples about the indispensability of personalized search are rendered moot with very simple additions to the search query.