Answer:
A language family is a group of languages that share a common ancestor in the past. The largest language families are the Indo-European and Sino-Tibetan. The Indo-European spans all of Europe and Russia as well North and South America as both English and Spanish are in this group. The Sino-Tibetan group is East Asia and South Asia.
Step-by-step explanation:
The languages in a language family are related in they shared a common ancestor at some point in our prehistory. Within language families there is a subsequent division into language branches as even groups of languages within language families can be more or less alike. The number of language families in the world is somewhat controversial because some like to general and emphasize the interrelatedness of languages and they only identify as low as 14 major language families. Others say there are much more at 147. The two largest language families are the Indo-European and Sino-Tibetan languages. Some believe the situation is even more diverse still and that there are thousands of languages in areas where there is a lot of linguistic diversity like Africa for example. The 4 language families often cited there may not represent all the intricacies of how these languages evolved.