It really depends for what purpose you are learning the language.
If you want a really popular language, I believe that Chinese Mandarin is the second (if not most) spoken language in the world. Although, if you want to go on a holiday somewhere, i highly suggest you learn the language most commonly spoken there. If your doing it for a study score or such, then the government/organisation scoring your education should have a website about what languages are most highly scored. (although, over here in Australia, Most languages have a high study score, or something similar.)
If it's for personal interest, I really can't help you. Although, there are several "Free" start up lessons for most subjects. Try some of them and see which one you like, and base your decision off that.
My research shows German and French are the most useful for British people followed by Spanish, these three are also the best for Americans to learn.
The figures only show native speakers, so, Putongua-Chinese is first and Spanish second, but that doesn't mean they're the best for you to learn. It's obvious English is generally the most useful. It has millions of 'second language' speakers, usually the people you're likely to need in, say, India, but the official stats.
German is the most useful for British people, then French, they too have business etc, importance far beyond their native speaker base.
What is the best source to learn the IT in English language
The best way to learn American English is to live in the states. When you are surrounded in American culture you will learn the language quicker.
The best language to learn singing in Europe is English because it is the world's most spoken language.
best way is to live in an English language country for a few months
I want to learn english language,please.
The best way to learn to speak English perfectly is to take classes at a local college. You can also buy Rosetta Stone to learn a language.
English is the hardest language to learn hun'.
English is one of the most difficult languages to learn. People who have a difficult time speaking a language probably speak it as a second language. The best time to learn a language is in a person's younger years. People who try to learn a second language when older may have a more difficult time perfecting their skill in that language.
Also try language pod 101 online classes. You can learn hows to speak and read any language, including English.
If you are interested in teaching English, the best available location would be nearby ESL schools, or English as a Second Language. You can then teach immigrants english in an English-speaking country.
If the official language of your country is English, then yes. They will make you learn English at school.