To use accents, forward, e.g. 'dijó Dios, sea la luz', or backward, e.g. 'à', tildes, e.g. 'ñ', etc., one types that figure before the letter upon which it is to go, but something else must be enabled, an international keyboard: my system's default is 'US', but going into the 'Layout' tab under 'Keyboard' under 'Settings' in the system menu permits a change to 'US Intl'; be warned, however, that on my system two 'Intl' options were found: one which is 'US altgr-intl', which you will not want, and the other without 'altgr-' in the name. Note that when you type like this, the mark preceding the letter upon which it goes will not appear when you've entered it: it appears with the letter to which it belongs only after the whole combination
useful yet tricky
More than just such special marks, which really by the computer are considered part of the character, not just an addition, (e.g. ñ is 'n-yay', though that's cheating since Spanish itself considers that one letter for having its own sound: on a computer the regular letter with the mark is overall a 'special character'), other special characters become possible using this keyboard layout.
The right-side 'alt' key, on this layout, becomes useless for its normal functions: using Firefox, for instance, one can no longer hit that and forward and back, but must use the left-side alt key; this is because this layout re-designates the key for the purpose of the international characters, and also so you may actually enter ' marks and such: by pressing that right alt key and simultaneously pressing the apostrophe key (which is what is used for the forward accent; the upper-left corner has the back-accent and tilde) one gets not an accent, but an apostrophe (similarly on the back-accent and tilde key, the latter which is selected using shift like any other superfigure on a keyboard, followed by the letter it should be combined with, or by itself using the right alt key in combination with shift all pressed simultaneously with the key upon which tilde is the superfigure).
As for special characters, press any key in combination with the right alt key to obtain one, at least for those which will produce it, for a taste:
Which are the following keys in tandem with that alt:
As you can see, f, g,h,j and ' produce only normal characters, the last of which you knew as aforementioned above; the last row of keys (z,x,c,v,b,n,m,,,.,/) inputs:
And don't forget to try adding shift to any of these combos, e.g. with that last row one gets:
And it's worth mention, that the ˙ figure is itself a mark to be combined with other figures, used in ancient Greek and who knows what other languages (in that particular one as a period), e.g. ȧ, ḃ, ċ, etc., as is the ̉ figure, (right-alt + shift + ? all simultaneously and ? pressed one more time while still holding that alt and shift), e.g. ẻ, Ả, ̉
The wonderful part of all this is: it works in any application that runs on your Linux system. : )
Now if I can figure whether one can also combine marks! [ed. see below]
There are beyond these still more combinations for marks, possible with the international US keyboard, such as §, obtained by typing simultaneously shift+right alt + > + s (double-tapped).
Be wary, however, of this one issue: at times the system may assume a character belongs to one mode of writing or another, and change that in the app or system, such as suddenly wanting to operate from right to left (RTL), opposed to our left to right (LTR), though when Iǘe when IǘeuIǘueIǘuuIǘuIǘuIǘuIǘuIǘuÏǘuIǘuIǘuIǘuIǘuIvúǘI¨ǘ !!!!! [ed. Ahhh, sweet accidents: forgetting momentarily that I'm typing on a layout requiring different behavior to type 'I've', I've discovered how to combine figures; it took me a few times re-typing 'I've' as 'Iǘe' in order to surmise it, but the way has become clear: it requires the desired marks to be input in correct order, in this case the quotation mark (shift + the apostrophe key, no right alt) must be input preceding the input of the apostrophe key (no alt, no shift), followed by the letter upon which those marks are to go, provided that letter is supported; I wanted to know this sort of thing for ancient Greek, which has combined accenting; these aren't important to you if you don't know about them, but are if you need them, such as ṹ--tilde and forward accent combined with a 'u'; the rule: forward and back accents (e.g. apostrophe or `) are input after the other mark]
ahem...though when I've encountered that behavior I was still able to type LTR, except punctuation marks were being placed left of the sentence....err... nevertheless RTL should come in handy for Semitic languages, and stumbling upon the functionality 'learned' me a few things. ;)
For some figures there are shortcuts. For example, instead of hitting apostrophe + u, right alt + u will give ú; in fact, this will work for any of the vowels, áéíóú, (which you may have caught above).
obtained by typing shift + " + [samke key as ", but NO RIGHT alt] + u
obtained by typin
shift + " + I or U
[how I was clued-in: https://answers.launchpad.net/ubuntu/+source/openoffice.org/+question/20570]