There are situations when you have to optimize website which is not in English. However, Google search algorithm has been designed to rank any website irrespective of its language. Search Engine Technology is not dependant on any particular language. However, you should avoid mixing 2 languages together when working on SEO. Either go with Language 1 or Language 2. Do not mix them. Just my own experience.
Yes it does pay important role. Most of the people around the globe search content in English Language. Just dont mess up with 2 different languages. If your business promotion is local only than you should go for your local language.
Thanks Tarini.. You and mascot removed my ambiguous, Finally. Actually I'm waiting to get someone say something on mascot. I think it is really a nice compliment that'll help to others who really want it.