Why is the letter ‘f’ used instead of 's' in old-fashioned spellings?
In genuine old-style printing it can appear that the letter f is used in place of the letter s. However, it is not the letter f, but a long form of the letter s (derived from handwriting styles), which looks very similar to f but does not have a complete cross-bar. It is not used at the ends of words, and in words where there is a double s, it is sometimes paired with a short s (which results in a compound letter like the German double-s (or `sz') symbol `ß'). It fell out of fashion with printers rather suddenly in about 1780.
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