Chapter 9 of Jobes and Silva is about the relationship between the LXX and the NT. I thought their discussion of the relationship between the language of the LXX and NT was worth a few quotes here. The LXX and NT share a common language, yet there is "much linguistic diversity" throughout the literature.
An additional consideration, however, brings the LXX and the NT even closer together, namely, the indisputable fact that the NT writers knew and used the OT in its Greek form. (184)
A distinction needs to be made between the influence of the LXX on the NT thought (to be discussed later in this chapter) and its influence on NT language. And with regard to the latter, a further distinction needs to be made between matters that affect the structure of the language and those that do not. (186)
Thus, for example, when Luke uses the expression και εγενετο ( = וַיְהִי = "and it came to pass" in the King James Version), it would be pointless to deny that, under the influence of the LXX, he is imitating the biblical style. But this is a matter of phraseology rather than syntax in the strict sense...
... the NT authors never -- except when quoting the OT directly -- use the peculiar combination of a finite verb with a participle of the same (or similar) verb in imitation of the Hebrew infinitive absolute construction, such as πληθυνων πληθυνω ("increasing I will increase" = הַרְבָּה אַרְבֶּה; Gen. 3:16) (187)
After noting a couple exceptions that, to Jobes and Silva, merely prove the rule, they wrap it up.
In the end, we have to recognize that the influence of the Greek OT on the language of the early Christians was, on the whole, limited to the use of technical or semitechnical terms distinctive of Hebrew theology or Jewish customs... the influence in question is primarily extralinguistic (cultural or conceptual) in nature. (189)