... not and don't have to etc. 27 must, can't and needn't with the perfect infinitive Present and past tensesPEG chapters 1 7 -1 8 1 246789 10 11 12 13 14 16 17 18 19 20 21 23242527282930 31 3327 ... 1 CONTENTS Articles PEG chapter I 1 Articles: a/ an 2 Articles: the 3 Articles: a/ an, the 4 Articles and possessive adjectives 5 a/ an and one Auxiliary verbs PEG chapters 1 0 -1 66 Auxiliary verbs ... 12 Question tags after negative statements 13 Question tags after affirmative statements 14 Question tags: mixed 15 Auxiliaries followed by full or bare infinitive 16 Auxiliaries: mixed 17 ...