The former colonial power, the Netherlands , left an extensive vocabulary. These Dutch loanwords, and also from other non Italo-Iberian, European languages loanwords which came via Dutch, cover all aspects of life. Some Dutch loanwords, having clusters of several consonants, pose difficulties to speakers of Indonesian. This problem is usually solved by insertion of the schwa . For example, Dutch schroef [ˈsxruf] → sekrup [səˈkrup] . Many Indonesian vocabulary ending "-i" (.:administras-i) also are known from the Dutch vocabulary influence "-ie" (.:administrat-ie). All the months from January (Januari) to December (Desember) used in Indonesian are also derived from Dutch. It is estimated that 10,000 words in Indonesian language can be traced to the Dutch language.