On 20 July the English fleet was off Eddystone Rocks , with the Armada upwind to the west. That night, in order to execute their attack, the English tacked upwind of the Armada, thus gaining the weather gage , a significant advantage. At daybreak on 21 July the English fleet engaged the Armada off Plymouth near the Eddystone rocks. The Armada was in a crescent-shaped defensive formation, convex towards the east. The galleons and great ships were concentrated in the centre and at the tips of the crescent's horns, giving cover to the transports and supply ships in between. Opposing them the English were in two sections, Drake to the north in Revenge with 11 ships, and Howard to the south in Ark Royal with the bulk of the fleet.
The Spanish phonemic inventory consists of five vowel phonemes ( /a/ , /e/ , /i/ , /o/ , /u/ ) and 17 to 19 consonant phonemes (the exact number depending on the dialect  ). The main allophonic variation among vowels is the reduction of the high vowels /i/ and /u/ to glides— [j] and [w] respectively—when unstressed and adjacent to another vowel. Some instances of the mid vowels /e/ and /o/ , determined lexically, alternate with the diphthongs /je/ and /we/ respectively when stressed, in a process that is better described as morphophonemic rather than phonological, as it is not predictable from phonology alone.