The band descriptors say that a band 8 in Grammatical Range and Accuracy is writing where:

* there is a wide range of grammatical structures

* The majority of the sentences are error-free.

Accuracy

Some believe that majority is more than half but compare this statement with one from band 7 which says, “produces frequent error-free sentences.”  Sentences at band 8 must be more correct than just frequently; assume that most of them must be correct.

Remember that at band 8 the examiner may be slightly more lenient with errors in complex grammar, but simple grammar should be accurate.

Areas where students often make errors include:

* Articles (a, an, the, zero article)

* Prepositions

* Subject-verb agreement

* Overusing present continuous

Range 

Here, you must show a great variety of structures, ideally complex grammar.

Some advanced grammatical structures that students often use include:

* Modal verbs (can, could, would, must)

* Passive voice

* Relative clauses

Band 8 requires using more than just the above, however.   Some examples of advanced grammatical structures follow.

Conditional sentences (If…then)

Most students are familiar with these sentences yet avoid them because of the combination of tenses required.  

If governments implemented and enforced measures, pollution could be reduced.

Band 8 students use more advanced forms of conditional sentences, including those without if.

Were governments to implement and enforce measures, pollution could be reduced.

It is also possible to use if + adjective rather than an entire clause.

If possible, governments should create public service campaigns regarding reducing fossil fuels.  (=if it is possible) 

If necessary, strict fines should be given to factories that do not reduce their emissions. (=if it is necessary).

Relative clauses

Most students are familiar with using which and that in their writing but rarely attempt higher-level usage of relative clauses.   These include:

* Relatives with expressions of quantity

* Relatives with prepositions or connectors.

Examples:

There are numerous measures that can be taken to reduce air pollution, many of which require governmental intervention.

Researchers have discovered that microplastics, many of whose effects are still unknown, have been found in sea creatures that are later eaten. 

The number of full-time students fell to 80,000 in 1985, after which the figure remained stable until the end of the period. 

Inversion

Inversion is an example of a high-level grammatical structure that few students attempt.  There are several different ways to create inversion.   In all of them, the verb and subject are inverted as in question order.

Rarely/ barely/ hardly/ never/ not only (at the beginning of a sentence)

Not only should citizens use their cars less, but they need to use less electricity in their homes also.

(=Citizens should use their cars less and they should also use less electricity in their homes)

Never has it been so important to adopt measures to protect the environment. 

(=It has never been so important to adopt measures to protect the environment)

Inversion is also created with only + then/ later/ / by/ after, and not until when they begin a sentence or subordinate clause but here the inversion comes in the main clause.

Not until governments step up their efforts to reduce pollution will we see light at the end of the tunnel.  

(=We won’t see light at the end of the tunnel until governments step up their efforts)

Only by looking at the matter in further detail can we understand its complexity.