In Finland, a person must have a surname and can have up to three given names. Surnames are usually inherited patrilineally, while given names are usually chosen by a person's parents. Finnish names come from a variety of dissimilar traditions that were consolidated only in the early 20th century. The first national act on names came into force in 1921, and it made surnames mandatory. Between 1930 and 1985, the Western Finnish tradition whereby a married woman took her husband's surname was mandatory. Previously in Eastern Finland, this was not necessarily the case.Finnish given names are often of Christian origin (e.g., Jukka from Greek Johannes), but Finnish and Swedish origins are also common.In Finnish, the letter ""j"" denotes the approximant [j], as in English you. For example, the two different names Maria and Marja are pronounced nearly identically. The letter ""y"" denotes the vowel [y], not found in English, but similar to German ""ü"" and French ""u"". ""R"" is rolled. The stress is always on the first syllable in Finnish. For example, Yrjö Kääriäinen is pronounced [ˈyrjø ˈkæːri.æinen]. Double letters always stand for a geminate or longer sound (e.g., Marjaana has a stressed short [ɑ] followed by an unstressed long [ɑː]).Pronunciation of Swedish names is similar, but long vowels are not doubled and the stress may be on any syllable. Finland has a long bilingual history and it is not unusual for Finnish speakers to have Swedish surnames or given names. Such names may be pronounced according to Finland–Swedish phonology or, depending on the person named, the person speaking and the language used, a Fennicized variant.When writing Finnish names without the Finnish alphabet available (such as in e-mail addresses), the letters ""ä"" and ""ö"" are usually replaced with ""a"" and ""o"", respectively (e.g., Pääkkönen as Paakkonen). This is not the same, but visually recognizable; since they are not linguistically umlauts, they cannot be substituted with ""ae"" and ""oe"" as in German.