The modern Māori alphabet has 15 letters, two of which are digraphs: A E H I K M N O P R T U W NG and WH. The five vowels have both short and long forms, with the long forms denoted by macrons marked above them - Ā, Ē, Ī, Ō and Ū. Attempts to write Māori words using the Latin script began with Captain James Cook and other early explorers, with varying degrees of success. Consonants seem to have caused the most difficulty, but medial and final vowels are often missing in early sources. Anne Salmond records "aghee" for aki (In the year 1773, from the North Island East Coast, p. 98), "Toogee" and "E tanga roak" for Tuki and Tangaroa (1793, Northland, p216), "Kokramea", "Kakramea" for Kakaramea (1801, Hauraki, p261), "toges" for toki(s), "Wannugu" for Uenuku and "gumera" for kumara (1801, Hauraki, p261, p266, p269), "Weygate" for Waikato (1801, Hauraki, p277), "Bunga Bunga" for pungapunga, "tubua" for tupua and "gure" for kurī (1801, Hauraki, p279), as well as "Tabooha" for Te Puhi (1823, Northern Northland, p385).