The phrase that only exists in exams

'Last but not least' appears in examination answers far more often than in anything else written in English, and examiners have learned to read it as a sign of a memorised phrase rather than a developed thought.

This is not because the phrase is wrong. It is because it is a connective that marks a list and carries no other information, and lists are the structure students reach for when they have four points and no argument. The phrase is a symptom: what the examiner is actually noticing is that the fourth point is not connected to the first three except by the order in which they appear.

Corpus evidence makes the pattern visible. Several phrases that are heavily taught — 'on the other hand', 'in a nutshell', 'all in all' — occur in learner writing at many times their rate in published prose, while the connectives that do most of the work in real argument are less memorable and less taught: 'which means', 'even so', 'in which case', 'the difficulty is'. The second group earns its place because each one makes a claim about the relationship between two ideas. The first group mostly announces that a new idea is arriving.

The practical move is not to avoid the taught phrases, which would be a different kind of performance. It is to test each connective by asking what it asserts. If 'however' can be replaced by 'and' without changing the meaning, it was not doing any work and its presence is noise. If it cannot, the sentence is carrying an argument and the connective is the part that shows it.

The exercise takes one pass through a draft and tends to remove about a third of the linking words.