... chapter 33 99 Infinitive used to express purpose 10 0 Clauses and phrases of purpose Keys to Practical Exercises 10 9 10 9 11 1 11 1 11 2 11 3 11 4 11 5 11 6 11 7 11 8 12 0 Exercises Articles Articles: a/ an ... 2 A PRACTICAL ENGLISH GRAMMAR EXERCISES CONTENTS Articles PEG chapter I Articles: a/ an Articles: the Articles: a/ an, the Articles and possessive adjectives a/ an and one Auxiliary verbs PEG chapters ... chapters 1 0 -1 6 Auxiliary verbs Auxiliaries conjugated with do/does/did Auxiliary verbs Auxiliary verbs 10 Additions to remarks, using auxiliary verbs 11 Agreements and disagreements with remarks,...