Language requirements for PhD programs?

<p>For example, in most Mathematics PhD programs I saw that you have to learn a foreign language to communicate in math, or something like that. Has anyone been through this? Is it as difficult as I think it may be? The only foreign languages I've had any background with is Greek and Spanish, although little of each, and usually I'm seeing for these PhD programs languages like French or German. Has anyone done this requirement without any knowledge in these areas? How difficult was it?</p>