Personal pronouns (like I, we, and you) are important in letters and memos. In such documents, it is perfectly appropriate to refer to yourself as I and to the reader as you. Be careful, however, when you use the pronoun we in a business letter that is written on company stationery, since it commits your company to what you have written. When stating your opinion, use I; when presenting company policy, use we.

The best writers strive to achieve a style that is so clear that their messages cannot be misunderstood. One way to achieve a clear style is to minimize your use of the passive voice. Although the passive voice is sometimes necessary, often it not only makes your writing dull but also can be ambiguous or overly impersonal. Here's an example of the same point stated in passive voice and in the active voice:

PASSIVE: The net benefits of subsidiary divestiture were grossly overestimated.
[Who did the overestimating?]

ACTIVE: The Global Finance Team grossly overestimated the net benefits of subsidiary divestiture.


The second version is clearer and thus preferable.

Of course, there are exceptions to every rule. What if you are the head of the Global Finance Team? You may want to get your message across without calling excessive attention to the fact that the error was your team's fault. The passive voice allows you to gloss over an unflattering point—but you should use it sparingly.