Lower-case f is an inconveniently-shaped letter. In order to stop the top-right-hand side of the letter bumping into a tall successor you need special ligatures in English at least for ff, fl, fi, ffl, ffi and those five are sufficiently venerable to appear in the Alphabetic Presentation Forms block of Unicode.
What about Irish and Gaelic, where f lenites in many sentences to fh? In my old Flamingo copy of The Best of Myles, there is no special ligature for it, so there’s a huge gap in the middle of the word seanfhocal “old word”. How does it look in your browser?
seanfhocal, fhàgail, fhèin
The two easy options in hot metal printing are to make your own fh or to choose a typeface where the widest part of the f is the crossbar.
Digital typography gives us another option, which is to simply print the h over the f’s ball terminal, which is a terminal in the shape of a ball, though I do keep misreading it in my head as being like “poet laureate”. How bad this looks depends mostly, I think, on whether you’ve had this drawn to your attention (sorry) and how new your spectacles are.
Scottish Gaelic provides another difficult letter combination:
fàs, fàinne, fàilte
This deserves a ligature of its own in fonts where the top of the f overshoots.
See also: Typography Deconstructed’s Type Glossary.
The immediate family members in Scottish Gaelic are?m?thair, athair, br?thair, all of which are clearly related to other familiar European languages, and?piuthar, “sister”, which looks odd. Irish is yet odder at first glance, with?dearth?ir meaning “brother” and?deirfi?r meaning “sister”.
I’ve been reading David Stifter’s Sengoidelc, a readable and reassuring text about Old Irish, the written Irish of the 8th and 9th centuries, which contains?at least part of the?explanation. It turns out that in Old Irish there were two letters?s. One of them lenited by turning into an?h, a bit like?s?in Gaelic becoming?sh pronounced /h/, but the other one turned into an?f, and the main word that began with that sort of an?s was siur, meaning “sister”.
What seems to have happened in Scotland is that the nominative case form was back-derived from the?lenited form phiur?and assumed to be piur. Conversely in Ireland the nominative form won out, and they say?si?r, but mainly, I think,?for non-biological sisters, like nurses and nuns. A further difference here: Scotland retains the disyllabic form, whereas in Ireland it’s been simplified to a long vowel.
But why in Ireland do they say?dearth?ir and?deirfi?r for your biological siblings? Enter eDIL, the Electronic Dictionary of the Irish Language, which has entries for derbr?thair and derbsiur, “true brother” and “true sister” respectively.