The count in ordinary English
Four is the English cardinal for 4: the integer after three and before five. It names a size of set, a digit, and, by extension, teams, scores, and objects that come in that quantity. The sense is stable enough that the word can look as if it had never travelled. It has. The origin of the word four is not a later import from French or Latin. It is a native Germanic numeral that has been in English since the Old English period, attested before 1150. The number stayed put; the consonants and the number of syllables did not.
How it reached modern English
Old English used fēower, also spelled feower, and in some dialects with shorter or rounded vowels. The form could mean the cardinal itself and, in context, four times. It was sometimes declined and sometimes left uninflected, as early English numerals often were.
Middle English inherited the word as a family of spellings rather than a single shape: four, foure, fower, feour, feouwer, and in southern and western texts vour, with the same initial voicing that turned fox-type words into v-forms in Kent. The extra syllable thinned away. By early modern English the everyday form was the monosyllable still written four. Scots fower keeps a two-syllable outline closer to the Old English word. None of this is borrowing. Historical dictionaries class the English numeral as inherited from Germanic, with first evidence already in Old English. French quatre and Spanish cuatro are relatives that arrived by other routes; they did not replace fēower.
The Germanic step, and a consonant English lost
Behind Old English stands Proto-West Germanic feuwar, and behind that Proto-Germanic fedwōr (handbooks also cite a slightly different reconstruction of the ending). Gothic still shows the inner stop in fidwōr. North and West Germanic dropped that middle consonant, which is why English four, Dutch vier, and German vier have no d in the middle. A leftover of the older cluster is cited from Old Norse naming: fjaðryndaland, a district counted as four hundreds. The inner consonant is written in Gothic, then gone from the West Germanic line that produced English. That loss is ordinary reduction. The initial f- is the harder problem.
An Indo-European root that should not have given f-
The deeper source is Proto-Indo-European kʷetwóres, with a neuter kʷetwṓr. That root is one of the better-attested numerals in the family. Latin quattuor, Greek tessares (with combining tetra-), Sanskrit catur, Lithuanian keturi, Old Irish cethir, Welsh pedwar, Albanian katër, and Old Church Slavonic četyre all point back to it.
Regular Germanic treatment of an initial labiovelar kʷ would have been expected to yield an hw- onset, giving something on the order of hwedwōr rather than fedwōr. That expected form is not what the daughter languages show. Comparative handbooks therefore reconstruct an irregular pre-Grimm shift of kʷ to p, producing petwṓr, after which Grimm’s law turns p into f. The usual motive offered is analogy with the next numeral, pénkʷe, five: the p- of five pulled four into the same labial series. The account is widely repeated and still marked as incomplete. Etymological surveys note that the Germanic consonants are not explained to everyone’s satisfaction; influence from five is the leading proposal, not a proof sealed by a dated sound law.
The same kʷ-to-p change is not unique to this word. Oscan petora and Welsh pedwar show labial outcomes of the same root in other branches. Those parallels make a p-form easy to believe. They do not, by themselves, prove why Germanic applied it here and not in every kʷ-word.
A popular shortcut says that Grimm’s law simply turned kʷ into f. That is too tidy. The regular Germanic outcome for the labiovelar is hw-, which is why what and which still begin with wh- in English spelling. Four did not take that path, which is why it no longer looks like Latin quattuor.
Kin that English also borrowed later
Once that Germanic f- is granted, the near family is dense: Dutch and German vier, Old Frisian fiower and fiuwer, Old Norse fjórir, Danish fire, Swedish fyra, West Frisian fjouwer. English later took in a second layer from Latin and French built on the same Indo-European root but never filtered through fēower: quarter, quart, quartet, square, squad, quarantine, quadruple. The language therefore holds two strata. One is the native count-word. The other is a set of learned and Romance four-words that look nothing like four because they kept a Latin qu- or a French derivative of it.
Native derivatives stay on the Germanic stem. Fourth continues Old English fēorða / fēowertha. Fourteen continues fēowertīene. Forty continues fēowertig; the missing u in forty is a spelling split inside one family, not a different etymon. Fortnight is fourteen nights. Farthing was a fourth of a penny, from Old English fēorthing, the ordinal made into a coin-name.
French speakers who meet English four sometimes map it to French four, the word for an oven. That French noun comes from Latin furnus and has nothing to do with the numeral. The French number is quatre. The oven-word is a lookalike, not a cognate.
Uses that grew around a fixed sense
The cardinal meaning did not wander. What multiplied were names for things grouped by fours. On all fours is eighteenth-century in that wording, with an earlier on all four in the fourteenth century. Four-letter word as a euphemism for a short vulgarism is recorded from 1923. Four-in-hand named a carriage driven with four horses by the 1790s and, a century later, a necktie knot. Games and sport added further labels: a four in cricket, a four in rowing, fours in cards and poker. These are overlays. They do not rewrite the numeral.
The f- as a dating mark
The useful residue is the mismatch with regular sound change. English four should, if the labiovelar had behaved as it did in the question-words, look more like an hw-word. It looks like five instead, because an old neighbour-numeral appears to have dragged it onto an f- before the Germanic consonant shift froze the result. Gothic fidwōr still carries the inner d that English dropped on the way from fedwōr to fēower to four. The count is the same in every period. The consonants are the history.