Do you thing learning English is usefui or useless Please li

Undoubtedly learning English is of great importance.
Here are some of the main reasons:
- English is the international language of diplomacy,business,science,law,technology,medicine,aviation,etc.
- After Mandarin,English is spoken by more people than any other language
- A strong command of English can mean more social mobility and greater social success.
- Even in China,proficiency in English can open the door to many good jobs.

I think learning english is useful, why?
I think the main reasons as following:
1. english is a tool helps us to know more information about the foreign countries;
2. english can help us to communicate with different friends from other countries;
3. english is an important technology we need to use in our work.