<https://www.youtube.com/watch?v=ihGfOC6H4ow> so in this video on Youtube, the
title uses "世界に", yet the thumbnail uses 世界的に. What is the difference, why
couldn't they simply say "世界に有名Youtuber" (they didn't use a な(!)?). Any
explanation would be appreciated, thanks :)
CC BY-SA 3.0
2016-10-31T11:21:16.727
40533
2016-11-01T13:48:14.943
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question
usage
世界に vs 世界的に, when to use?
世界的に means internationally.  
世界に means in the world.

世界的に有名 = famous worldwide/internationally  
世界に有名 = famous in the world.
CC BY-SA 3.0
2016-10-31T11:28:33.683
40534
2016-10-31T11:28:33.683
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answer
First, 世界に有名 is ungrammatical. It should be 世界で有名 as others say.

に as in 世界に注目されている denotes the agent of passive voice, in short, it means
（日本のYoutuber）who is stared **by** the world.
CC BY-SA 3.0
2016-10-31T16:15:52.763
40547
2016-10-31T16:15:52.763
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世界的に means "world-famous", "international". 世界に means "in the world".

For example:

> それは世界に一つしかない。 That is only one in this world.  
>  彼は世界的なYoutuberだ。  
>  He is famous youtuber in the world. 世界に有名 isn't natural.
CC BY-SA 3.0
2016-11-01T13:48:14.943
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2016-11-01T13:48:14.943
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answer