2. Spanish
If we were only to look at native speakers, Spanish has its nose in front of English with about 400 million speakers. If you want a language that will open up whole continents to you, Spanish is your best bet. As with all the languages on this list, the politics of language and associated identity are highly disputed: ask Catalan or Quechua speakers if Spanish is their local tongue and you will get a very different answer. But it is certainly the primary language of most of South and Central America, Spain, and, ahem, large swathes of the US.
3. English
If you’re reading this article, you may be one of the 360 million-odd native English speakers, or one of the half a billion people who speak it as a second language. This indicates the remarkable success of English as the lingua franca of business, travel and international relations. The relative ease with which English can be picked up (especially compared with Chinese) and the pervasive soft power of US culture means that English will continue to dominate the world stage. For some, English is still synonymous with opportunity and a better quality of life.
4. Hindi
India has 23 official languages, with Hindi/Urdu chief among them. Whether this is one language — Hindustani — or two dialects, is still fiercely debated. Spoken mainly in northern India and parts of Pakistan, Hindi uses devnagri script, while Urdu uses Persian notation. At the time of writing, the debate about its role in Indian education and society has once again flared up: Prime Minister Narendra Modi, a Hindu nationalist, is seeking to have Hindi displace English in the southern Indian states as the primary language of official communication and education, a strategy that has been met with resistance. If you ever travel in the Indian subcontinent, a little Hindi will get you a long way. Plus, this is the language that gave us shampoo, jungle, jodhpurs and bungalow — what’s not to love?
5. Arabic
Recent numbers put Arabic at around 250 million native speakers. But this is another instance of numbers not telling the full tale: Arabic, like Chinese, is so vastly different in its respective dialects as to be effectively a number of languages, grouped as one for the sake of convenience. Modern Standard Arabic is a primarily written form, closely related to the Classical Arabic of the Quran. However, the spoken forms of Arabic in, say, Oman and Morocco are so different that a couple of philosophy professors from these countries might be able to discuss the finer points of the ancient texts while struggling to order lunch.
Source : babbel