A colleague asked about the distinction between "differ from" and "differ with." 

In R.W. Burchfield's update of Fowler's usage guide, he writes that "in the sense to be unlike, distinguishable," differ is followed by from. If the writer means to show disagreement or a difference of opinion, differ is followed by with. Bryan A. Garner says that differ from "typically appears whenever two things are unlike."

Here are examples:

My home computer differs from the one I use at work; mine is a PC, and the one I use at work is a Mac.

I differ with my colleague about computers: I think my Mac is better than his PC.

A colleague asked about a preposition the other day. (Copy editors are funny that way.) He was puzzling over this set of sentences:

Hornsby’s boss called the search unlawful and forbade Hornsby to conduct searches without first getting permission from his supervisor.

Hornsby’s boss called the search unlawful and forbade Hornsby from conducting searches without first getting permission from his supervisor. 

Is the best form "forbid to (infinitive)" or "forbid from (verb+ing)"? I turned to Bryan A. Garner's usage book, "Garner's Modern American Usage." Garner says that "forbid to" is the more formal usage, but "forbid from" is also commonly used. I can accept either of the sentences above as correct, but we might be safer in choosing "to (infinitive)." 

Later, I checked Bernstein's "The Careful Writer," which says forbid "takes the preposition to (infinitive)." Fowler considered "forbid from" unidiomatic, but Burchfield in his Fowler update noted that "forbid from" was becoming more common. 

As for the past tense of "forbid," forbade is preferred. The second syllable sounds like "bad."