All dialects of Old English had diphthongs. Like monophthongs, diphthongs appear to have had short and long versions. In modern texts, long diphthongs are marked with a macron on the first letter. The short versions behave like short monophthongs, and the long versions like long monophthongs. Most Old English diphthongs consist of a front vowel followed by a back offglide; according to some analyses they were in fact front vowels followed by a velarized consonant. The diphthongs tend to be height-harmonic, meaning that both parts of the diphthong had the same vowel height (high, mid or low).