A language uses the same word to represent the numeral <i>one</i> and to indicate the non-specificity of a noun.  In German, the word <i>ein</i> serves this dual purpose.  In the clause <i>Ich habe einen Hund gekauft</i> 'I have one dog bought,' <i>ein</i> 'one/a' may stress that the speaker has purchased one and only one dog, or it may act as an indefinite article.

<br><br><b>Reference</b><br>
Dryer, Matthew S. 2008. Indefinite Articles.
In Haspelmath et al (2008), chapter 38.
Available online at <a href="http://wals.info/feature/38">
http://wals.info/feature/38</a href>.

