One woe is past; the one woe, or the first woe. "Woe" ( ἡ οὐαί) is feminine; perhaps because expressing the idea of tribulation, such words being generally feminine in the Greek. Some have thought that these words are a further announcement by the eagle of Revelation 8:13; but there is nothing to lead us to suppose that they are not the words of the writer.
And, behold, there come two woes more hereafter. Omit "and:" behold, there cometh yet two woes hereafter. The verb is singular in א, A, and others; the plural is found in א, B, P, and others. Alford says, "singular, the verb applying simply to that which is future, without reference as yet to its plurality."
But probably οὐαί, although written as a feminine in the preceding clause, being really indeclinable, is treated as a neuter; and thus the singular verb is made to agree with the neuter plural, in conformity with the rules of Greek grammar.
The second woe extends from this place to Revelation 11:14, and the third woe is contained in Revelation 11:14-19, especially in Revelation 11:18.