The Different Kinds of Sleep - BrainFacts
www.brainfacts.org › The-Different-Kinds-of-SleepMar 20, 2012 · These four types of brain waves, and others discussed below, are important criteria that have been used to define four distinct stages of non-REM sleep. Obviously, falling into a deeper and deeper sleep as the night progresses is actually a gradual, continuous process, but these four stages still provide a convenient means of describing the ...
"People of different kind" or "People of different kinds"
english.stackexchange.com › questions › 321119Apr 23, 2016 · As kind is a countable noun (used in this sense), it must have an article when singular. So it is either people of different kinds, or people of a different kind. However whilst the former is used to refer to two or more kinds of people e.g. The anti-EU voters comprise peoples of many different kinds, the latter is used to apply to a single kind of people, who are different to some reference group, or groups e.g. UKIP voters are people of an entirely different kind to all others.