pri

In honor of Tu B'Shvat, the Academy of the Hebrew Language posted a page about the Hebrew word for fruit: פרי - p'ri ( I prefer this spelling over pri, since it emphasizes the vocalized shva.  We also find a few instances of peri - with a segol - in Biblical Hebrew.)

They point out that in the Tanach, p'ri only appears as a collective noun (שם קיבוצי). This means that while it is in the singular form, it can refer to a group of more than one of the object. (See this page from Safa Ivrit, which gives many other examples of Biblical collective nouns. The question of whether a particular noun is a singular or a collective noun causes much debate among the commentators.) So the Biblical p'ri can either refer to an individual fruit or "fruit, produce" as a whole.

In Rabbinic Hebrew we first find the plural perot פירות. They quote the Mishna (Berachot 6:1) as showing the mix of the two forms:

על פֵּרות האילן הוא אומר: בורא פרי העץ.
On fruits (perot) of the tree (ilan), he blesses "borei p'ri ha'etz"

Although the rabbis spoke post-Biblical Hebrew, they generally used the Biblical forms of the word for the blessings. So here we have p'ri as the plural, as well as etz instead of ilan for "tree".

The Academy also writes that p'ri is related to the verb פרה, meaning "to be fruitful". This is better than Klein who writes that p'ri comes from פרה. For as Tur Sinai writes in his footnote to פרה, the verb actually derives from the noun, since the noun has many cognates in Semitic languages, where the verb does not.

Reader Shaul wrote to me:

What is the etymology of peri? Is it at all related to English "fruit," which ultimately derives from Latin "fructus" and Proto-Indo-European before that? 

The two words do not seem to be related. As the Online Etymology Dictionary (and others) point out, the Proto-Indo-European root is *bhrug, meaning "to enjoy", which is distant from p'ri meaning "fruit".

However, there are other possible candidates for related English words. For example, in the comments on our post about tapuach תפוח, we discuss the possibility of the Latin pirum (the origin of the English word "pear"), being related to p'ri (it is also discussed in this old book). Other English words possibly connected (although with plenty of theories to the contrary) include "berry", "bear" (as in bear fruit), and "fertile" (both from the PIE root *bher, which we've shown may be related to the Hebrew words apiryon אפריון and parnasa פרנסה.) See also this article, which tries to explain how many of these roots are connected, and also adds in the Hebrew יבול yevul, meaning "produce". But this is all just speculation. And as it's Tu B'Shvat - let's focus on the fruits of the Land of Israel!