To adjust any font effects, select some text, right-click, and choose Font from the shortcut menu. All standard effects are available in the Font dialog box: color, bold, italic, bold italic, underline, shadow, emboss, and superscript/subscript. You can also adjust the elevation of superscripts and subscripts in the Offset box.
If you're planning to deliver your presentation on a large screen, avoid italicized fonts, which often end up looking like wavy blobs. You can use underline instead, to emphasize a word or phrase, but underlining is traditionally reserved as a substitute for italic. If you absolutely must emphasize a word, bold is probably your best choice.
Replacing Fonts Throughout a Presentation
If you're trying to change all the Times New Roman in a presentation to Garamond, you might be tempted to change the Title Master and Slide Master, and call it a day.
Unfortunately, if you've applied any manual formatting to individual slides, the "link" between the slide and its master might be broken. In that case, even if the master is updated, the slide might not make the switch.
To truly change all occurrences of Times New Roman to Garamond, choose Format, Replace Fonts. Choose Times New Roman from the Replace drop-down list; choose Garamond from the With list. Click OK to apply the change throughout the presentationeven in the masters. This solution is especially useful when you inherit a presentation created by someone who used a font you don't have.
Note
This technique changes only the font; you can't use the dialog box to change point size.