• Verb forms Auxiliary Verbs

  Auxiliary or “helping” verbs are verbs that are used to complete the meaning of other primary or “main” verbs in a sentence. In the example we looked at above, are is an auxiliary to the main verb, learning.
  The three primary auxiliary verbs—be, have, and do—are used to create different tenses, to form negatives, or to ask questions. For example:
• “I am working on my project.” (present continuous tense)
• “She does not work here anymore.” (negative sentence)
• “Have you seen my keys?” (question)
  There are also modal auxiliary verbs (often just called modal verbs), which are used to express modality—that is, possibility, likelihood, ability, permission, obligation, or future intention. These are can, could, will, would, shall, should, must, may, and might. They are distinguished by the fact that they are unable to conjugate into different forms, and they are only followed by a verb in its base form. For example:
• “I will be there tonight.” (future intention)
• “She can write very well.” (ability)
• “May I be excused from the table?” (permission)
• “We must finish this today.” (obligation)

  Infinitives

  Infinitives are the most basic construction of a verb. When we talk of a verb as a general concept, we usually use the infinitive form, which is the uninflected base form of the verb plus the particle to. For instance:

  
  
  
  

  to run to walk to read to be

  
  

  to learn to act

  Infinitives can be used as nouns, adjectives, or adverbs in a sentence, but they do not actually function as verbs—they are used to express an action as a concept, rather than what is being done or performed by the subject of a clause. For example:
• “I love to run.” (functions as a noun)
• “I wish I had something to do.” (functions as an adjective)
• “I run a lot to stay healthy.” (functions as an adverb)

  Participles

  Participles are forms of verbs that either function with auxiliary verbs to create the continuous and perfect verb tenses, or as adjectives to modify nouns. Every verb (except the modal auxiliary verbs) has two participle forms: a present participle and a past participle.
  The present participle is always the base form of the verb + “-ing.” Although the spelling of some verbs changes very slightly to accommodate this suffix, every verb takes “-ing” for the present participle.
  We use present participles with the auxiliary be to form continuous tenses, as in:
• “Can’t you see that I am reading?” (present continuous tense)
• “I was watching that.” (past continuous tense)
• “They will be arriving soon.” (future continuous tense)
  The past participle is usually the same as a verb’s simple past tense form, which is made by adding “-d” or “-ed” to the end of the verb. However, many verbs are irregular, meaning they do not follow this spelling pattern, and they have different past tense and past participle forms. (We’ll look at regular and irregular verbs later on.)
  The past participle is used with the auxiliary have to form the perfect tenses:
• “You have worked long enough.” (present perfect tense)
• “We had seen too much.” (past perfect tense)
• “They’ll have arrived before we get there.” (future perfect tense)
  We can also use participles as adjectives to add description to nouns. Though they still relate to action, they are not functioning as verbs when used this way. For example:
• “The mother looked down at her smiling child.”
• “I could tell by the exhausted look on his face that he needed sleep.”