Line spacing

Word bases its default line spacing on the vertical metrics tables of individual fonts. If two different fonts on the same line have different vertical metrics -- which is very often the case, especially when different writing systems are involved -- then the font with the largest metrics determines the Word line spacing. The way to correct this is to manually set the line spacing to an absolute, rather than relative value.

In the Word Paragraph / Indents and Spacing dialogue, see the Lines spacing setting about halfway down on the right side. If you select Exactly from the drop down list, you can then specify linespacing in pt units, in the same was as you specifiy type size. The pt measurement will be an absolute distance between the baseline of one line of text and the next line of text.

If you want to exactly match the appearance of double-spaced Times New Roman, you will probably have to experiment a bit with the pt measurment, because what Word considers double-spaced is not double the pt size of the text but double the individual font metrics, which will usually be quite a lot larger than double the pt size.