Nowadays, some employees speak English at work even though it's not their mother tongue. Does it bother you?

English is widely accepted business language in most of the countries and there is no way to feel more about it. I won't mind if someone is trying to communicate in English.

Workplace language depends and varies from country to country. Though I do sincerely believe English is the Universal language and should be implemented in professional environments. However this is not true in some cases.

English speaking should be adopted especially in Multinational or Multi-cultural work environments where people from different parts of the world together to focus on operations.

I do not mind when i notice native language speakers communicating to one another in their mother tounge. It is their right and they're in their comfort zone.

However it seems highly inappropriate when2 native language speakers e.g. start speaking in Arabic during a meeting while there are people who speak other languages. It's rude and it should be avoided in my personal opinion. For board, executive, advisory etc meetings English should be utilized as the official language for communications. However if all the board members are composed of arabs then they may use Arabic as such. Same goes for other languages.

Apologies if the answer offends anyone.

Whatever you can learn and wherever you can use it, is beneficial because you get more practice of the language and thus you become better. 

it depends on how it was spoken because not all of us can speak english fluently, some people doesn't use the combination of words properly resulting to wrong grammar. it bothers if thats the case

not at all, english is a language where everyone , all cultures can communicate . Its a language that brings us all to one understanding

To some people , it is ok .to others , it isnot recommended.I won't buy food from a german restaurant whose employees speak German as I don't understand the language or the know the nature of food if they don't help me to understand.

Not really,it is the business spoken language 

never ,,, its2nd language around the world now.

Learning should be encouraged and not become a cause for botheration.

yes definately why cant they be what they are instead they talk in alien language or the language which is not theirs

No