In this verse, Adam is referred to in the singular, yet both the preceding and the following text refer to both Adam and Eve:
The use of the pronoun they in 2 Nephi 2:22–23 is especially egregious since they refers to Adam and Eve, yet the preceding text (at the beginning of verse 22) refers only to Adam. One could perhaps propose rewriting the beginning of verse 22 in the plural:
Of course, it is extremely doubtful here that we have a primitive error in the earliest text for the beginning of verse 22. The switch to Adam and the singular pronoun he seems to be just as intentional as the surrounding use of Adam and Eve and the plural pronoun they.
In a personal communication (8 November 2003), Kelly Taylor points out that the switch to Adam at the beginning of verse 22 may be explained as a generic reference to Adam and Eve. Consider the following examples of pronoun shifting in the account of the creation of Adam and Eve in the King James Bible:
The second passage is especially noteworthy. Here the Hebrew text uses √ffladfflam three times (numbered as 1, 2, and 3) to refer to generic man (meaning ‘human being’, not ‘male’). The King James Bible translates only the second occurrence as man. In the two other cases, the King James text has Adam. The last example is particularly relevant since in this instance Adam is directly used to refer to both Adam and Eve (“male and female”). In the same way, the Book of Mormon text can be said to use Adam alone at the beginning of 2 Nephi 2:22 to refer to both Adam and Eve.
Summary: Maintain the use of Adam and the singular pronoun he at the beginning of 2 Nephi 2:22; the usage here refers to both Adam and Eve and parallels the use of Adam in Genesis 5:1–2.