Use sentence grammar consistently and with accuracy
(i) Take care over different aspects of sentence grammar that can affect the accuracy, cohesion and fluency of writing, especially: subject-verb agreement in complex sentences; form and use of a range of tenses; word order in subordinate clauses.
(ii) Understand that when writing longer texts, good writers keep checking back in the course of writing, and check for consistency of tense as well as other grammatical forms, repetition and syntax
(iii) Understand and use a full range of modal verbs where appropriate, e.g. in describing a hypothetical situation in the past or future