Many governments encourage their citizens to learn a global language, such as English, as well as their own. I believe the advantages of this policy outweigh the disadvantages.
The main benefit is opportunity. People who speak a widely used language can apply for jobs in international companies, study at foreign universities and read research and news from around the world. A country with a multilingual population is also more attractive to investors, because businesses know that staff can communicate with overseas clients. In a wider sense, knowing a global language makes it easier to communicate with people from other cultures, which promotes understanding and cultural exchange. Travelling, making friends online or watching films in the original language all become more rewarding.
There are, however, disadvantages. Learning a second language takes considerable time and money, and students from poor families may be unable to afford quality lessons or private tutoring, so inequality grows between those who master the language and those who do not. There is also concern that emphasis on a foreign language might weaken the national language, especially if children begin to use it for study and entertainment and neglect their own. Finally, students can feel under pressure, as their results in the language may affect their university admission or job prospects, causing stress.
Nevertheless, I think these problems can be limited. Governments can provide free lessons and resources in public schools, so that learning does not depend on family income, and they can protect the national language by teaching it with equal seriousness and promoting its use in media, literature and official life. Reasonable expectations and supportive teaching would also help reduce pressure on learners.
In conclusion, learning a global language alongside one's own brings important economic and cultural benefits, and with fair access and protection of the national language, the advantages are greater.