The 25th letter of the Dutch alphabet causes confusion among many Dutch learners.
We now know that the 25th letter is Y. But is it? Sometimes, the 25th letter is written as Y, sometimes as IJ.
In Dutch, the combination of i and j constitutes a vowel, which sounds a bit like English 'i' in 'hi': ij. Old typewriters used to have a separate key for the letter ij but on modern keyboards, the Dutch have to type two letters (i and j).
Because the Dutch still regard ij as one letter, they always capitalize both I and J if they occur at the beginning of a sentence or a proper name.
het IJsselmeer | a Dutch lake
IJburg | A district in Amsterdam
IJs smelt bij 0 graden Celsius. | Ice melts at 0 degrees Celsius.
When the Dutch read the alphabet out loud, they say 'ij' even if they actually write 'y'.
They normally pronounce 'y' as 'ie' (see also [vowel combinations](#/lesson/SpellingAndPronunciation.12)) but when 'y' is mentioned in the alphabet, it is always pronounced as 'ij' [vowel combinations](#/lesson/SpellingAndPronunciation.12) again).
The letter "y" is not used in originally Dutch words; it only appears in borrowed words, e.g. baby, derby, and lyceum.
The letter "y" is also the only letter in the Dutch alphabet that is called by its name: "Griekse y (Greek y)" or ypsilon (after the Greek letter).
The article The Dutch letter IJ gives you a good idea of the letter IJ issue.