How to type the fada
Every device can type á é í ó ú; almost none of them tells you how. The five answers below cover practically everyone. Capital fadas (Á É Í Ó Ú) work the same way with Shift held.
iPhone & iPad
Press and hold the vowel on the keyboard until a row of accented forms pops up. Slide your finger to the acute one (á) and release. That is the whole trick, and it works in every app.
Android
The same press-and-hold works on Gboard and Samsung Keyboard: hold the vowel, slide to the acute form. If the acute form is missing, add Irish under Settings → System → Languages → on-screen keyboard languages.
Windows
Set your keyboard to “Irish” or “English (United Kingdom) Extended” under Settings → Time & language → Language. Then AltGr (the right-hand Alt) + the vowel gives the fada: AltGr+a → á. Without that layout, the Windows emoji/symbols panel (Win + .) has the accented characters under Symbols → Latin.
Mac
Press and hold the vowel (the iPhone trick came from here) and pick the acute form. Or press Option+e, release, then the vowel: Option+e, a → á. Both work everywhere on the system.
Chromebook
Add the “Irish” or “UK Extended” input method under Settings → Device → Keyboards and inputs. Then, as on Windows, AltGr + vowel produces the fada.
The lookalikes to avoid
Word processors sometimes substitute a straight “accent” character (´) beside the vowel instead of on it, and some fonts render a lookalike that is not the real accented letter. If you can place the cursor between the mark and the vowel, it is the wrong character: our validator rejects exactly these, because they survive every spellcheck and ruin every engraving. Copy from a trusted source instead: every saying on this site has a copy button that carries the exact bytes, fadas included.