Origins
The verb 'follow' is one of the most fundamental words of spatial and social relationship in English, describing the act of going after, accompanying, obeying, and understanding. Its etymology is solidly Germanic, though the deeper Indo-European connections remain a matter of scholarly debate.
Old English 'folgian' (also spelled 'fylgian' in some dialects) meant 'to follow, accompany, pursue, come after, obey, serve.' It was a weak verb (Class II), and its meaning encompassed both physical following (going after someone in space) and metaphorical following (obeying a leader, adhering to a rule, practicing a religion). This breadth of meaning was already present in the earliest Old English texts and is shared by the cognates in other Germanic languages.
Proto-Germanic *fulgāną is reconstructed from the consistent reflexes across the Germanic family: Old English 'folgian,' Old Saxon 'folgon,' Old High German 'folgēn' (modern German 'folgen'), Old Frisian 'folgia,' Old Norse 'fylgja,' and Gothic — where the word is not attested, with 'laistjan' (to follow, from 'laists,' footprint, track) used instead. The absence in Gothic is notable and suggests that even in Proto-Germanic there may have been competing words for the concept of following.
Proto-Indo-European Roots
The deeper etymology of Proto-Germanic *fulgāną is uncertain. Several proposals have been advanced. One connects it to PIE *pleh₁- (to fill) or *pelh₂- (full), suggesting that the original sense was 'to fill in behind,' 'to make full the company of,' or 'to follow to the full extent.' This would link 'follow' to 'full,' 'fill,' 'plenty,' and 'folk' (a people, a full company). Another proposal connects it to a root meaning 'to go' or 'to move,' but this lacks strong phonological support. The connection to 'folk' is particularly interesting: Old English 'folc' (people, nation, troop) may share the same root, suggesting that a 'folk' was originally a following — a group of people who move together, who follow the same path or leader.
The phonological development from Old English 'folgian' to modern 'follow' involves the insertion of a glide vowel between the /l/ and /g/, which became /w/. The velar fricative /ɣ/ (the sound of Old English 'g' between vowels) weakened and became the semivowel /w/, producing the '-low' ending. This is the same sound change visible in words like 'borrow' (from Old English 'borgian') and 'sorrow' (from Old English 'sorg'). The final '-ow' spelling was standardized in Middle English.
The semantic range of 'follow' in modern English is impressively wide. The physical sense (follow a person, follow a path) is primary. The temporal sense (Monday follows Sunday) extends the spatial metaphor to time — events 'follow' each other as if walking in a line. The logical sense (the conclusion follows from the premises) transfers the metaphor to reasoning — conclusions 'follow' from evidence the way a person follows a guide. The social sense (follow a leader, follow a religion, follow advice) maps physical accompaniment onto obedience and adherence. The cognitive sense (I follow your argument, do you follow?) equates understanding with the ability to keep up — if you can follow someone's reasoning, you can stay on the same path they are walking.
Figurative Development
The compound 'follow-up' (first attested in the late nineteenth century) describes a subsequent action that continues or completes an initial one. The phrase 'follow through' (from golf and other sports, extended metaphorically) describes completing an action after the initial impulse. 'Follow suit' (from card games) means to match someone else's action — to play the same suit of card, hence to imitate.
The noun 'follower' has undergone a remarkable modern transformation. For centuries, a follower was a retainer, an adherent, a disciple — someone who literally or figuratively walked behind a leader. In the twenty-first century, 'follower' has been transformed by social media into a word for someone who subscribes to another person's digital output. This new sense preserves the core etymology — a follower is still someone who goes where another goes — but the 'going' is now informational rather than physical. The asymmetry between 'followers' and 'following' in social media (one follows many, many follow one) would have been familiar to medieval speakers, for whom the word described exactly this kind of asymmetric relationship between a lord and retainers.
In Old Norse, the cognate 'fylgja' developed a remarkable supernatural sense alongside its ordinary meaning. A 'fylgja' was a personal guardian spirit — a supernatural being, often appearing in animal form, that followed a person throughout their life. Seeing one's own fylgja was typically an omen of death, as it suggested the spirit was preparing to separate from its living charge. This mystical elaboration of 'following' is unique to Norse and enriches the word's cultural history beyond its purely linguistic development.
Modern Legacy
The relationship between 'follow' and 'lead' forms one of the fundamental conceptual pairs of English — and indeed of human social organization. Every follower implies a leader, and every leader implies followers. The two words are semantically complementary but etymologically unrelated: 'lead' derives from an entirely different root (PIE *leit-, to go forth). Their pairing in English reflects a social reality rather than a linguistic kinship.