First, I want to acknowledge that not all questions of biblical interpretation can be settled based on grammar—in fact, some arguments are based on grammar (such as the “faith of Christ” vs. “faith in Christ” argument of recent decades). But some mistaken readings of Scripture happen because of a failure to attend to grammar.
“I know the plans I have for you,” declares the Lord, “plans to give you hope and a future.” (Jeremiah 29:11; NIV, adapted)
I have seen this quotation from Jeremiah 29:11 as the signature on some emails and on wall plaques. The passage is often taken as proof of God’s personal plan for each believer. But the “you” here is plural, and is about God’s intent to restore the Israelites, who are going into Babylonian exile. While “you”-plural can mean “each of you,” here it is collective. The captive nation is addressed collectively as “you.” In the American South, “y’all” would be a good translation. That the plural “you” is collective is clear in the context, because in verse 14, God promises to bring the captives back: “I will gather you from all the nations and places where I have banished you” (NIV, italics added). The promise of Jeremiah 29:11 applies to a group, not an individual.
A similar example of the importance of recognizing the plural “you,” this time from the New Testament, is in Philippians 2:12, 13:
12 Therefore, my dear friends, as you have always obeyed—not only in my presence, but now much more in my absence—continue to work out your salvation with fear and trembling, 13 for it is God who works in you to will and to act in order to fulfill his good purpose. (NIV)
When these verses are read to urge greater personal effort towards improvement (“work out your salvation”) or as encouragement, that we do not have to depend on our own efforts (“it is God who works in you”), the plural “you” is being ignored. The plural is obvious in the very next verse (2:15) where the readers are called “children of God.” The point is corporate—the Philippian church, harassed by outsiders (1:28-30), need to hold together strong as a group, trusting in the knowledge that they are not on their own but their unity is sustained by the Lord.
The difficulty in both cases is that well-stated phrases are attractive on their own and get used for other purposes. When reading the Bible in English it can be difficult to tell the difference between a plural “you” and a singular one. But the use of good commentaries can protect against such misreadings.