Though class membership is ultimately determined by morphology (the class prefix and the noun's concords) and not semantics, it is obvious from comparing the class contents of various languages that there are some tentative semantic trends. The strongest trend (which is basically a rule) is that all class 1 nouns are human, and non-human nouns that begin with the prefix are therefore in class 3 (in fact, there are no human class 3 nouns in Sesotho). In many other languages, however, class 1 contains "animate" nouns, and may therefore also contain some non-human nouns.