What is the largest language family? In terms of languages? In terms of speakers?
For number of languages, Niger-Congo with 1524 living languages. For number of speakers, Indo-European with nearly 3 billion speakers.
How many language families are there?
There are 136 language families
Which language is spoken in the most countries? How many countries?
English [eng]. It is spoken in 125 countries, as an indigenous language or by a substantial immigrant group.
How can I learn to speak language X? Can you send me a dictionary or language learning materials?
We do not teach specific languages such as Spanish, Turkish, Mohawk, or Tok Pisin. Rather, we teach linguistics (how to analyze a language) and language learning techniques (how to learn a language on your own).