English with Isabel
Grammar7-minute readUpdated 2026-07

The 5 errors that flag you as Band 6

The fastest way to improve your Grammatical Range & Accuracy band is to eliminate the five most common errors—subject-verb agreement, countable vs uncountable nouns, prepositions, word form confusion, and comma splices—that examiners flag as Band 6 signals.

Error 1 — Subject-verb agreement

The subject and verb must agree in number. Plural subject → plural verb. The trap: when the subject is far from the verb, students lose track.

Wrong

The number of accidents have risen. One of the students are absent. Each of the children have a book.

Right

The number of accidents has risen. (subject = number) One of the students is absent. Each of the children has a book.

Error 2 — Countable vs uncountable

Some nouns can’t be pluralised in English even when they look like they should be. Information, advice, research, news, equipment, furniture, knowledge — all uncountable. No informations, no advices, no researches.

Use much/little for uncountable
much information, little advice, much research.
Use many/few for countable
many studies, few examples, many countries.
Use a piece of / an item of for countable bits of uncountable
‘A piece of advice’, ‘an item of furniture’, ‘a piece of research’.

Error 3 — Preposition mistakes

Wrong prepositions are the single most common Band 6 error. The ones examiners notice most:

depend ON (not depend of/from)
“The result depends on the weather.”
discuss [something] (no ‘about’)
“We discussed the issue.” not “We discussed about the issue.”
good AT (not good in)
“She’s good at maths.”
interested IN (not interested on/about)
“He’s interested in design.”
different FROM (not different than/of)
“The result was different from what we expected.”
consist OF (not consist on)
“The course consists of three modules.”
in / on / at — the time hierarchy
in 2024 (year), in March (month), on Monday (day), on 14 March (date), at 3pm (time).

Error 4 — Word-form confusion

Mixing noun, verb, adjective and adverb forms of the same root. Examiners flag this as a Lexical Resource error, not just a grammar one.

Wrong

The economy growth is steady. (using noun as adjective) She is a success writer. (noun used where adjective needed) This is more easier than the last one. (double comparative)

Right

The economic growth is steady. (adjective) She is a successful writer. This is easier than the last one. (just -er, not more + -er)

Error 5 — Run-on sentences and comma splices

Joining two complete sentences with just a comma is grammatically wrong in English. Use a period, a semicolon, or a coordinating conjunction.

Wrong (comma splice)

Online learning is convenient, it allows students to study at their own pace.

Three correct fixes

Online learning is convenient; it allows students to study at their own pace. Online learning is convenient. It allows students to study at their own pace. Online learning is convenient, and it allows students to study at their own pace.

Spot the error

  1. 1

    Which sentence is grammatically correct?

    Pick one. You'll see why straight away.

  2. 2

    The number of homeless people _____ doubled over the past decade.

    Pick one. You'll see why straight away.

Want Isabel to mark your task?

Submit a writing or speaking task for per-criterion feedback within 48 hours. $29 per task, $99 for a full mock.