in the first person singular, is, which is pronounced with a Z sound, in the third person singular, and are, which is pronounced with an sound, in the plural and second person singular. (Its present subjunctive is be, as in "I suggest that you be extremely careful", though that is not irregular, as all verbs use the infinitive/imperative form for the present subjunctive.) It also has two past tense forms: was, which is pronounced with an sound in US English, for the first and third persons singular, and were, which is pronounced with an sound, for the plural and second person singular (although there are certain subjunctive uses in which were can substitute for was, as in "If I were you…" or "I wish I were there"). The past participle is been, which is pronounced with an sound in US English, and the present participle and gerund forms are regular: being. For more details see Indo-European copula. As mentioned above, apart from its other irregularities, the verb do, which is pronounced with an sound, has the third person present indicative does & past participle done pronounced with short vowels: . The verb have, which is pronounced with an sound, has a contracted third person present indicative form: has (weak pronunciation ). This is formed similarly to the verb's past tense had. The verb say displays vowel shortening in the third person present indicative (although the spelling is regular): says . The same shortening occurs in the past form said . (Compare the diphthong in the plain form say .) For shortened forms of certain verbs and of their negations (s, re, won't, etc.), see English auxiliaries and contractions. Coincident forms In regular English verbs, the past tense and past participle have the same form. This is also true of most irregular verbs that follow a variation of the weak conjugation, as can be seen in the list below. Differences between the past tense and past participle (as in sing–sang–sung, rise–rose–risen) generally appear in the case of verbs that continue the strong conjugation, or in a few cases weak verbs that have acquired strong-type forms by analogy—as with show (regular past tense showed, strong-type past participle shown). However, even some strong verbs have identical past tense and participle, as in cling–clung–clung. In some verbs, the past tense, past participle, or both are identical in form to the basic (infinitive) form of