Start here · the long version
What comparisons really asks you to write
Comparison language sets two quantities against each other and says which is larger, by how much, and in what terms — as a multiple, as a gap, or as a rank.
Three ways to say the same difference
Given two numbers, English offers three quite different ways to relate them, and choosing between them is a decision about what your sentence is for. You can state a multiple — “twice as many” — which is the most compact and the most easily checked. You can state a gap — “exceeded X by twelve points” — which is what you want when the size of the difference is the point. Or you can state a rank — “the second highest” — which is what you want when the position matters more than the distance.
A response that only ever uses one of the three reads as thin however accurate it is, because every comparison in it has the same shape. A response that picks the right one each time is doing something an examiner can see: it is reading the chart rather than transcribing it.
The grammar is where these break, and it breaks in predictable places. “Twice as many” needs “as” on both sides and a plural noun in between. “Exceed” takes its object directly and never “exceed to”. Comparatives take “than”, and a comparison with no “than” is a sentence waiting for something that never arrives.
Multiple“twice as many as”, “three times higher than”. Compact, and the reader can verify it instantly.
Gap“exceeded by”, “fell short of”, “the difference was”. Use when the size of the difference is the point.
Rank“the highest”, “second only to”, “the least common”. Use when position matters more than distance.
Countable or not“fewer cars” but “less energy”. “Number of” for things you count, “amount of” for a mass.
Where the accuracy is checked
Comparison is the most falsifiable language in Task 1: a reader with the chart in front of them can confirm or refute every one of your claims in seconds. “Twice as many” is either true or it is not, and getting it wrong is not a vocabulary slip — it is a misreport of the data, which reaches Task Achievement.
That is also why the hedged forms are worth knowing. “Almost twice as many”, “just over a third”, “roughly comparable” let you be accurate about a chart whose values do not land on round numbers, which is most charts. Reaching for the clean multiple when the data does not support it is the commonest way this vocabulary produces a false sentence.
What it costs you to skip this
A response without comparison language does not fail; it flattens. Every sentence becomes “X was 40% and Y was 20%”, and the reader is left to do the arithmetic that your sentence was supposed to do — which is precisely the work Task Achievement asks for. And an inaccurate comparison costs twice, because it is both a lexical error and a false statement about the data.
Where it stops applying
Only compare things the visual actually sets side by side. Two charts with different units are not comparable, and a multiple across them is invented. Superlatives need the whole set to be visible: “the highest” is a claim about every category on the chart, so it is false the moment one is off-screen or unlabelled. And do not compare a category with itself across years and call it a comparison — that is a trend.
