"... Besides the translator's insertion of καί in Isaiah 7:16 and ἀλλά in verse 17, we also noted earlier that the Greek sentence in verse 14 is constructed differently from its Hebrew counterpart. The Masoretic text successively contains a term (הָעַלְמָה‎) which can be read either as a verb or an adjective, a finite verb (הָרָה‎), and a participle (יֹלֶדֶת‎). If הָעַלְמָה‎ is taken as a verb, then it should be translated as “is pregnant.” This meaning will make more sense by taking into account the present aspect provided by the participle (יֹלֶדֶת‎). If one considers הָעַלְמָה‎ as an adjective, then it would still bear a present connotation as it is governed by the meaning of the participle (יֹלֶדֶת‎). In either case, the sentence structure seems to describe the situation of the woman in question: at the moment the statement is made, she is already pregnant and in fact on the point of giving birth. However, in the LXX, three coordinate verbs are used, all of them in the future tense (ἐλεύσεται ... καλέσεις ... καλέσει), thus constructing the sentence to refer to the near future. Even if “the presence of הִנֵּה‎ at the opening of the verse would call for a futuristic interpretation of [the copula],” as de Sousa has argued, it is worth noting, as Brown has correctly pointed out, that “while ... the Hebrew is vague about whether the conception had already taken place or would take place in the future, the Greek is not vague and the conception is definitely future” ..."

"... Much of the discussion over Isaiah 7:14 has to do with whether certain translations are justifiable. Is παρθένος (Parthenos) a reasonable translation of העלמה (almah)? Yes, Genesis 24:43 provides a precedent. Is “virgin” a reasonable translation of παρθένος? Yes, Revelation 14:4 associates παρθένος with sexual inexperience. But although these translations are reasonable, there is reason to think that sexual inexperience is not the prototypical characteristic of a παρθένος, even in G’s mind. Lincoln adduced many examples of παρθένος with the more general meaning of a woman who has not yet borne a child: Pausanias 8.20.4; Diodorus Siculus 20.84.3; Lycophron, Alexandra 1141,1175; Sophocles, Oedipus Rex 1462, and most clearly Sophocles, Women of Trachis 1216–1229, “where the dying Heracles implores his son to marry a παρθένος who has already been his own lover”. Similarly, the Septuagint has non-virginal uses of the word in Genesis 34:3 and Joel 1:8, and even in Isaiah 62:5 we encounter the phrase συνοικῶν νεανίσκος παρθένῳ, where the cohabitation (notably in the present tense) implies that not sexual inexperience but age appears to be what G had in mind ..."