A) Mac US Keyboard Layout Dead Keys (typed before base character)
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Option/alt-n = tilde
Option/alt-` = grave
Option/alt-e = acute
Option/alt-u = diaeresis/umlaut
Option/alt-i = circumflex
(Option/alt-c = c-cedilla)
ß is Option/alt + b.
å is Option/alt + a.
ø is Option/alt + o.
æ is Option/alt + '.
œ is Option/alt + q.
¡ is Option/alt + 1
¿ is Opton/alt + Shift + /
€ is Option/alt + Shift + 2
Note: These should work with all apps.
B) Mac US Extended Keyboard Dead Keys (typed before base character)
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Option/alt-` = grave
Option/alt-6 = circumflex above
Option/alt-w = dot above
Option/alt-e = acute
Option/alt-u = diaeresis/umlaut
Option/alt-i = horn
Option/alt-p = comma below
Option/alt-a = macron above
Option/alt-h = macron below
Option/alt-j = double acute
Option/alt-k = ring above
Option/alt-l = stroke overlay
Option/alt-z = hook above
Option/alt-x = dot below
Option/alt-c = cedilla
Option/alt-v = caron
Option/alt-b = breve
Option/alt-n = tilde above
Option/alt-m = ogonek
Option/alt-Shift-g = circumflex below
Option/alt-Shift-f = tilde below
Option/alt-Shift-s = inverted breve above
Option/alt-Shift-y = double grave above
Note: This keyboard can only be used with Unicode-savvy apps (not Appleworks or WordX).
C) Mac US Extended Keyboard Combining Diacritics (typed after base character)
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Option/alt-Shift-` = grave
Option/alt-Shift-6 = circumflex
Option/alt-Shift-w = dot above
Option/alt-Shift-e = acute
Option/alt-Shift-u = diaeresis/umlaut
Option/alt-Shift-i = horn
Option/alt-Shift-p = comma below
Option/alt-Shift-a = macron above
Option/alt-Shift-h = macron below
Option/alt-Shift-j = double acute
Option/alt-Shift-k = ring above
Option/alt-Shift-l = stroke overlay
Option/alt-Shift-z = hook
Option/alt-Shift-x = dot below
Option/alt-Shift-c = cedilla
Option/alt-Shift-v = caron
Option/alt-Shift-b = breve
Option/alt-Shift-n = tilde
Option/alt-Shift-m = ogonek
Note: This keyboard can only be used with Unicode-savvy apps (not Appleworks or WordX).
D) US International Keyboard Layout Dead Keys (typed before base character)
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` = grave
~ (i.e. shift-`) = tilde
^ (i.e. shift-6) = circumflex
' = acute and c-cedilla
" = diaeresis/umlaut
Note: This is the Windows PC style US International keyboard. OS X 10.6 includes this, but for earlier versions you can download one here.
(References on these charts refer to what you see in Keyboard Viewer, or when you look at the printing on the keys of the English (USA) physical keyboard. If, instead of using Keyboard Viewer, you are looking at a different physical keyboard with different printing on the keys, references may need to be transposed accordingly. For example, when using the US layouts with a French AZERTY keyboard, you must hit the key printed q to create an a. Pictures of Apple physical keyboards can be found here.)
For more info on keyboard issues, see this page.