What is the most difficult language in the world from your point of view,?

Most people I have spoken to on this subject have said that Mandarin is the most difficult to learn; I have no personal idea as I speak no Chinese.

My point of view is very limited.  I have read that Navajo and Inuit are the most difficult languages to learn; that maybe nobody who doesn't learn them in childhood can learn them.

Sentinelese... because it's the language on that uncontacted island where the missionary was killed by the natives.  It's is un documented, no one knows anything about it.  But since there's around 6,500 languages currently spoken on Earth, there could be a lot of hard ones.

The ones I've come across which seem hardest would be Gaidhlig, which unfortunately is kind of "my" language because I'm a Scot, Basque and Georgian.

Any language without an alphabetic type of writing. The only one I can think of is Chinese. Whither Russian, I learned a new alphabet, and was good to go.

But not possible in Chinese. Where every word is a symbol. And proper nouns have to be translated by a symbol the approximates the sound of a name.

Japanese, Chinese and Korean without a doubt are the hardest. Any East Asian language.

Not having experience with ALL the languages in the world, I hesitate to say with any degree of accuracy.

I think it's Arabic language it's to difficult 

No language is difficult, children learn them all the time. It is difficult for people to learn another language that has phonemes not used in their own language. The first thing they have to do is learn the different sounds and then learn to hear them and hearing them is not easy.

I'm not familiar with that many languages but I'd say Chinese is pretty difficult.