The central idea is that English spread mainly because of power, not just due to colonisation. David Crystal argues that the language became global because the societies that wielded real influence—economically, politically, and culturally—championed and used it as a tool to participate in international networks. English is the language of global business, science, technology, media, and diplomacy, so people learn it to access those networks and opportunities. Colonisation helped spread English, but the long-term and wide-reaching spread unfolds through the advantage and reach of English-speaking powers, which keeps reinforcing its status even beyond formal colonial ties. Technology and geography can explain some factors, but they don’t capture why English becomes the default in so many diverse contexts; religious reform isn’t the driving force Crystal identifies.

The idea being tested is how the positive or negative value attached to a word shifts over time. Amelioration is when a word takes on a more positive or favorable sense, sometimes extending to new contexts. Pejoration is the opposite: the word develops a more negative or disapproving sense. Classic examples help make this clear: "nice" once meant foolish, but now means pleasant; "awful" once meant full of awe, but now means terrible. A word like "sick" also shows amelioration when used in slang to mean excellent. So the statement that exactly captures this is that amelioration involves gaining a more positive meaning, while pejoration involves gaining a more negative meaning. Descriptions that talk about losing meaning, or about becoming more formal or about SAMPLEbroader/narrower scope, describe different kinds of semantic change and don’t capture the specific positive/negative shift these terms describe.

The main idea being tested is how a word’s range of meaning can expand over time—that is, the word starts to cover more things than it did before. This is semantic broadening. It happens when a term takes on new contexts or is extended metaphorically, so its referents grow and the word ends up in more situations than in the past. A classic illustration is broadcast. Originally it meant to scatter seeds widely across a field; now it also means to transmit radio or television signals widely. This shows the sense shift from a narrower set of meanings to a broader one. This differs from semantic bleaching, which would lose descriptive power or detail in a word’s meaning rather than add new scope. It also differs from narrowing, where a word’s meanings become more restricted. Semantics generalization is sometimes used as a synonym for broadening, but the description “broadens its meanings” aligns most directly with semantic broadening.

The main idea is that language is a social tool that evolves with its speakers. Language exists through use by people, not as a separate, fixed thing; as speakers change—their vocabulary, norms, technology, and ways of communicating—their language shifts to fit those new realities. Because people are continually changing, language changes too, and the only languages that don’t change are the ones that are no longer in use. This captures why the view emphasizes a direct link between how people live and how their speech evolves. The other ideas miss that connection: language isn’t fixed, change isn’t purely random, and it isn’t necessarily about getting better—it's about adapting to changing human use.