Theories and processes of change: the wave, S-curve and random fluctuation models, the influence of technology and society, and the functional and lexical processes of change.

What this dot point is asking

Edexcel wants you to explain the named theories of how language change happens and spreads, and to identify the word-formation and functional processes that drive change, applying them to data and texts. The exam tests this as modern-data analysis (identifying the processes behind new words) and as theory evaluation (weighing the models of how change diffuses). The key skill is to match the right process or model to the actual evidence, and to explain the mechanism and social cause, not merely to attach a label.

The answer

Change can be analysed on two axes: how it spreads and how new forms are made. Three models describe spread: the wave model (geographical diffusion), the S-curve model (rate of adoption) and random fluctuation (chance origin). Functional and substratum theories explain why change happens. A set of word-formation processes (borrowing, affixation, compounding, blending, clipping, acronyms, initialisms, conversion, eponyms) explains how new words are coined. Technology and social change accelerate all of these. Edexcel rewards naming the exact process or model and tying it to the evidence and its cause.

Theories of how and why change spreads

The three diffusion models are complementary, each capturing a different dimension. The wave model handles geography: an innovation in a city spreads to surrounding regions, weakening with distance, which explains regional patterns of change. The S-curve model handles rate: any single feature is adopted slowly by early users, then rapidly as it tips into the mainstream, then plateaus, which describes the life-cycle of a neologism or a sound change. Random fluctuation (Hockett) handles origin: many changes begin as chance variation, slips or playful coinages that happen to be picked up.

Beyond diffusion, two theories address cause. Functional theory argues that language changes to meet its users' needs: it gains words for new concepts (technology, social movements) and sheds redundant ones, filling lexical gaps as society changes. This is why each new technology generates a burst of vocabulary. Substratum theory points to language contact: when speakers of different varieties or languages mix, features cross over, so contact between dialects, or between English and other languages, drives change.

Processes of word formation

Technology and society as accelerators

Technology and the internet are the dominant engines of present-day change. They create lexical gaps (every new device and platform needs naming) that the word-formation processes rush to fill, and they create new genres of communication (texting, instant messaging, social media) with their own conventions. They also speed diffusion: a coinage can move from niche to global in months rather than the generations that older changes took, which is the S-curve compressed by mass connectivity.

Examples in context

A social-media coinage on the S-curve. The verb "to google" began as a brand name (an eponym), then underwent conversion to a verb ("I googled it"). A strong paragraph would name both processes (eponym becoming a verb by conversion), explain the mechanism (a proper noun generalised into a common verb because it filled a functional need, naming the new act of web searching), and tie its spread to the S-curve: slow while search engines were niche, rapid as the web became universal, now levelled off as a standard verb. The paragraph explains process, cause and diffusion together rather than just labelling.

Dialect contact and the wave model. A regional pronunciation feature spreading out from a major city (for example the diffusion of certain London features into surrounding counties) illustrates the wave model and substratum theory together. A strong paragraph would argue that the feature spreads outward from the urban centre, weakening with distance (wave model), and that the mechanism is contact between the city variety and surrounding varieties as people move and commute (substratum theory). It would note the wave model's limit, that social networks and prestige, not just geography, govern who adopts a feature, which is where modern sociolinguistics refines the simple ripple picture.

Try this

Q1. Describe the S-curve model and the wave model, and state what each is good at explaining. [4 marks]

• What the marker wants. S-curve: slow then rapid then levelling adoption, good for the rate of a single change; wave: spreads outward geographically weakening with distance, good for regional diffusion.

Q2. Identify the word-formation process in "brunch", "NASA" and "to text". [3 marks]

• What the marker wants. "brunch" is a blend (breakfast and lunch), "NASA" is an acronym (said as a word), "to text" is conversion (noun to verb).

Q3. Analyse the word-formation processes in modern data and explain how they illustrate the influence of technology and society. [16 marks]

• What the marker wants. Precise naming of each process with its mechanism, linked to functional theory (filling lexical gaps created by new technology and social realities), and a connection to a diffusion model where relevant.

A note on sources

This guide is AI-written and not individually human-reviewed. It reflects the Pearson Edexcel A-Level English Language (9EN0) specification and standard accounts of change (Hockett, functional and substratum theory, the S-curve and wave models). Verify current assessment structure and references against the official Pearson specification before relying on it.