Test your English in Johnny's new quiz app for phones and tablets, on both iOS and Android! To download the "Johnny Grammar's Word Challenge" app for free, visit our LearnEnglish website: http://bit.ly/1tVk59X We use the present perfect to talk about experiences in the past up to the moment of speaking. The present perfect is "subject + auxiliary 'have' + past participle". We often shorten 'have/has' to ''ve/'s'. I've eaten in this restaurant many times. To make the negative we add 'not' between the auxiliary 'have' and the past participle. I haven't had it before. The question form is auxiliary 'have/has' + past participle. Have you tried this vegetable dish?