1 The MBA Center Grammar Review for the TOEFL I. Verbs II. Nouns III. Pronouns IV. Modifiers V. Comparatives VI. Prepositions VII. Conjunctions 1 2 I. VERBS Verbs are the foundations of language and accordingly they are one of the most common questions in the Structure and Written Expression section. Although many of the questions involve the advanced cases, an understanding of the basic tenses is essential In this section we will be using four terms for the verb words. Let’s define them before we begin. Infinitive to be to live Dictionary be live Gerund being living Participle been lived Present Tense subject simple continuous perfect perfect continuous I live am living have lived have been living you live are living have lived have been living he/she/it lives is living has lived has been living we live are living have lived have been living they live are living have lived have been living present simple—Indicates a habitual action—something that is always true—for example, a train schedule or a scientific fact. This action does not actually need to occur at the moment of speaking. I live in Paris. (Generally speaking, I live in Paris.) I teach English. (Generally speaking, I teach English.) He eats lobster. (He generally enjoys eating lobster.) present continuous—An action that is occurring at the moment of speaking. An action in the present continuous must be occurring at the moment of speaking, as opposed to the more general present simple case. Be careful of “continual action” verbs, like to read, that are not necessarily occurring at the moment of speaking exactly. I am living in Paris. (At the moment of speaking, I am living in Paris.) I am teaching English. (At the moment of speaking, I am instructing a class or student.) I am eating lobster. (Right now, as I speak, I am eating lobster.) 2 3 present perfect—Refers to an action in the past that is connected to the moment of speaking. It does not necessarily mean that the action is still continuing, although in some cases, it does. Usually it is a past experience the speaker is using to demonstrate expertise on a subject. I have lived in Paris for ten years. (Ten years ago, I moved to Paris and I am still here. In the past, for a period of ten years, I lived in Paris, and that experience is important to the moment of speaking. I can recommend some restaurants.) I have taught English for ten years. (Ten years ago, I began teaching English, and I still am today. In the past, for a period of ten years, I taught English, therefore I can help you with your homework.) I have eaten lobster for ten years. (I began eating lobster ten years ago, and I still eat it today. I have eaten lobster before. In the past, I ate lobster, and that is why I hate it.) present perfect continuous—An action that began in the past and is still continuing. Always. Make a parallel between this tense and the present perfect. I have been teaching for ten years.(I began teaching ten years ago, and I still am teaching today.) Past Tense subject simple continuous perfect perfect continuous I lived was living had lived had been living you lived were living had lived had been living he/she/it lived was living had lived had been living we lived were living had lived had been living they lived were living had lived had been living past simple—Indicates a finished action. Something that has happened in the past and has no connection to the moment of speaking. I lived in Paris (In the past, I lived in Paris.) I taught English. (In the past, I taught English.) I ate lobster. (In the past, I ate lobster.) past continuous—An action that happens in the past and is interrupted by another action. This verb can never stand alone, it must have a complement verb. I was living in Paris when France won the World Cup. (During my action of “living in Paris,” France won the World Cup.) I was teaching English when the student got sick. (While I was in the middle of teaching, the student got sick.) I was eating lobster when the phone rang. (While I was eating, the phone rang.) past perfect—Usually used when there is more than one action happening in the past in a certain order. I had lived in Paris before I went to school in England. (First I lived in Paris, then I went to England.) 3 本文来源：https://www.wddqw.com/doc/ab48487d6729647d27284b73f242336c1fb9306a.html