Complex sentence: In Modern Greek (and since the Roman Imperial period), the letters and the letter combinations are pronounced (except when pronounced as semivowels), and a modern transcription renders them all as; but a transliteration distinguishes them, for example by transliterating to and.
Split into simpler sentences: In Modern Greek usage (and since the Roman Imperial period), the letters and the letter combinations may be pronounced. When so pronounced, a modern transcription renders them all as, but a transliteration still distinguishes them, for example by transliterating to and.