borrowed many words from Chinese without becoming a Sino-Tibetan language;
There has been a great deal of controversy about whether family trees
based on lexicostatistics are reliable. Those who doubt it point to the
possibility that cognate percentages might be strongly affected by vocabulary
borrowing, either in a negative or positive direction. For instance, Japanese
borrowed many words from Chinese without becoming a Sino-Tibetan language;
it has recently borrowed many words from English without becoming an Indo-European
language. Those who favor lexicostatistics argue that this sort of borrowing
is less common in the basic-vocabulary wordlists that they use.