Apply all caps and small caps

When you format text as small caps, Illustrator automatically uses the small-cap characters designed as part of the font, if available. Otherwise, Illustrator synthesizes the small caps using scaled-down versions of the regular capital letters.

Regular capital letters (top) compared to small-cap letters (bottom)

Select the characters or type objects you want to change. If you don’t select any text, the setting applies to new text you create.
Choose All Caps or Small Caps from the Character panel menu.

To specify the size for synthesized small caps, choose File > Document Setup. For Small Caps, type a percentage of the original font size for text to be formatted as small caps. (The default value is 70%.)

To change the capitalization style of text to uppercase, lowercase, title case, or sentence case, use the Type > Change Case command.