Radio Sunrise serves the West London community of mixed races. Punjabi speakers in the midst of English suburb. Look up what these two languages Punjabi and English have in common. In fact, English and Punjabi as well as other languages of northern India like Hindi and Gujarati are related. Something discovered by chance two hundred years ago by a multilingual English lawyer, Sir William Jones. 

"He was a judge who went up to India in 1783, but he studied languages, oriental languages, before he went. And when he got to India he became very interested in learning Sanskrit, which is the language of ancient India, which was first written about 500 A.D. And then he realised, he made this great discovery that Sankrit resembles in someway, has relationship with Greek and Latin and other languages. And he gave a very famous discourse in which he said that this was sprung from some common source".
It´s surprising that noone spotted the resemblances earlier. Take the numbers again for example, the Sanskrit on the right there is a strong resemblance to Latin and Greek on the left, but while one, two and three obvioused, four and five nedd a closer look to spot the connection.
Linguists have discovered rules that govern how sounds in different languages are related. Look at the words for "four", this is one of many examples where a word beginning with "q" in Latin say, is similar to a Greek word beginning with "t" and the Sanskrit word beginning with "k". These sound correspondences can reveal how apparently unrelated languages are members of the same family. 

"The question is how can you tell that a language as you looking at reflect a single original language and therefore form a family?. The only way you can do that is by finding sistematic similarities between these languages in every area of their grammar similarities and their sounds similarities in all the inflections similarities, and the syntax of the language are, and soforth. And the similarities have to be very precise, and they have to be interlocking for the assertion that these languages form a family; or to be believable you take a look at an English word like "tooth" and see that in Hindi is "dant", and that by itself it doesn´t mean very much. But you take a look at an English "ten" and it shows up in Hindi as "das", and you see the same pattern emerging: you´ve got an initial "t" in English and an initial "d" in Hindi. When you find that the word "two", the numeral in English, shows up in Hindi as "do" and you´ve got once again an initial "t" in English and an initial "d" in Hindi, you begin to think that perhaps this is not an accident". 

Linguists have now established that a whole range of languages streching from Iceland to India, form one family called Indo-European. They could even reconstruct an earlier ancestor of these languages Proto-Indoeuropean.