What conditions does an alien have to fulfill for acquiring citizenship through naturalization?

The conditions laid down for conferment of citizenship vary from country to country, usually they are:

(a) A minimum period of residence.

(b) Knowledge of the national language.

(c) By marriage, i.e., a woman marrying a citizen of a state may become ipso facto naturalized citizen of the country of her husband.

(d) By official appointment, i.e., on appointment as a government official a person may become a naturalized citizen.

(e) Purchase of property, i.e., when a foreigner purchases property in a for­eign country, he attains the citizenship of the country in due course of time.