(17) Words compete for survival in each language. Some researchers investigated what causes the rise and fall of English words in two ways. One is an experiment where thousands of participants read English- language stories and rewrote them to be read by other participants, who then rewrote them for others. The other is a linguistic analysis of English historical text data that cover the past two centuries. The researchers found that the competition among words is closely associated with how humans use language: words that are acquired earlier in life, more concrete, and more stimulating are more likely to survive. From the previous two experiments, they determined that there are at least over 7,000 languages in the world at this moment, but will these numbers increase or decrease in the future? These findings may contribute toward interpreting the patterns of language change over generations of English language speakers.