In M&F (Page 328) the second person forms of perfect subjunctive active do not have a macron on the last i; nor do the first person plurals.
In Wheelock, however, they have (Page 453).
Which is correct? Thank you.
Allen & Greenough give it short. However, I believe the quantity varied, especially in poetry: for example, in Catullus 5, line 10:
Dein, cum milia multa fecerimus
fecerimus has long i.
Thank you.
According to Sihler, §543,3, the latin perfect subjunctive is formed from *is-ī. With normal sound changes, this makes -erī-. Because of the likeness to the future perfect, the final i loses its quantity, though; except among early poets - and seldom seen metri causa in later poetry, and almost exclusively in the first and second person plural.