Charles Halton over at Awilum has a post on an article in Hebrew Studies that discusses linguistic data for distinguishing between Standard and Late Biblical Hebrew. The problem is one that is on-going in the field, with some scholars doubting whether linguistic evidence can be used for dating texts.
I posted a response to his entry, which I reproduce here:
I think the exile is the earliest point at which the change would be made, but it didn’t necessarily happen at that point. It certainly happened by 400, but it didn’t necessarily happen that late. That leaves us almost two centuries during which the change could happen. Not only is 200 years a long time, but these happen to be a rather important 200 years.
Many of the texts that we have trouble dating fall within that time period. This is especially important for me, since I am working on the last layers of the Pentateuch. If we could determine the time of the change from SBH to LBH, that might help me date H and the H redactor.
To tip my hand somewhat, I am currently leaning towards a pre-exilic date for the Priestly source (P), perhaps in the 8th century BCE, and an exilic dating for the Holiness layer (H). The H redactor is post-exilic, as it clearly shows signs of Aramaic influence. The problem is that if P and H are pre-exilic and exilic, then both of them should be written in SBH, since the date for the switch to LBH is probably later than the exile. That means linguistic data cannot help me distinguish P and H, but might help me distinguish H from the H redactor.