Unlike Windows, the Macintosh operating systems do not require you to install a special keyboard configuration to type letters with diacritical marks. The capability for the characters is ready for you from the time you turn your computer on for the first time.
The method for typing the characters isn't intuitive, however, although it's easy to master. The key is that to type a modified letter (such as an é, ü or ñ) you type a special key combination followed by the letter. For example, to type vowels with an acute accent on them (namely the á, é, í, ó and ú) press the Option key and the "e" key at the same time, then release the keys. This tells your computer that the next letter will have the acute accent. So to type á, press the Option key and the "e" at the same time, release those keys, and then type the "a." If you want it capitalized, the process is the same, except press the "a" and the shift key at the same time.
The process is similar for the other special letters. To type the ñ, press the Option and "n" keys at the same time and release them, then press the "n." To type the ü, press the Option and "u" keys at the same time and release them, then press the "u."
To summarize:
- á — Option + e, a
- Á — Option + e, Shift + a
- é — Option + e, e
- É — Option + e, Shift + e
- í — Option + e, i
- Í — Option + e, Shift + i
- ñ — Option + n, n
- Ñ — Option + n, Shift + n
- ó — Option + e, o
- Ó — Option + e, Shift + o
- ú — Option + e, u
- Ú — Option + e, Shift + u
- ü — Option + u, u
- Ü — Option + u, Shift + u
To type Spanish punctuation, it necessary to press two or three keys at the same time. Here are the combinations to learn:
- inverted question mark (¿) — Shift + Option + ?
- inverted exclamation point (¡) — Option + 1
- left angle quote («) — Option + \
- right angle quote (») — Shift + Option + \
- quotation dash (—) — Shift + Option + -
References: Macintosh: Typing Special Characters and Symbols (Apple.com), Accent Codes for the Macintosh (Penn State University), Mac OS X 10.5 Help (Apple.com)

