When the latter numbers are taken into account, the global figure for the number of those able to use English, even if not as a mother tongue or as a matter of preference, may be considerably higher than many quoted references suggest. David Crystal'sThe English Language (see below), for example, points to the possibility that the number of people who speak English as a secondary language could be much the same as for those for whom English is their mother tongue—contributing to a combined total in the region of 800 million speakers.