Auxiliary Verbs
[A2] English auxiliary verbs are the helping verbs that form tenses, aspects, questions, and negations. This module explains be, have, and do, and how they combine with main verbs to convey meaning.
Auxiliary verbs
Auxiliary verbs are helping verbs that work with a main verb to build meaning. They can show time, aspect, possibility, obligation, permission, and emphasis. In English, auxiliaries also help form questions and negatives without changing the main verb. The main auxiliary groups are be, have, do, and the modal auxiliaries.
Los verbos auxiliares son verbos de ayuda que acompañan a un verbo principal para construir significado. Pueden indicar tiempo, aspecto, posibilidad, obligación, permiso y énfasis. En inglés, los auxiliares también ayudan a formar preguntas y negaciones sin cambiar el verbo principal. Los grupos principales de auxiliares son be, have, do y los auxiliares modales.
Be auxiliary
Be is an auxiliary when it combines with another verb form. It is used to form continuous tenses with the -ing form, and passive voice with the past participle. Be changes form to match the subject and time, while the main verb stays in the needed form.
Be es un auxiliar cuando se combina con otra forma verbal. Se usa para formar tiempos continuos con la forma -ing y la voz pasiva con el participio pasado. Be cambia de forma para concordar con el sujeto y el tiempo, mientras que el verbo principal permanece en la forma necesaria.
Rule | 🇪🇸 Español Regla | Example | 🇪🇸 Español Ejemplo |
|---|---|---|---|
 Be + -ing forms the continuous aspect | 🧠 Be + -ing forma el aspecto continuo | She is studying now. | 🧠 Ella está estudiando ahora. |
| Be + past participle forms the passive voice | 🧠 Be + past participle forma la voz pasiva | The window was broken. | 🧠 La ventana fue rota. |
| The form of be agrees with the subject and tense | 🧠 La forma de be concuerda con el sujeto y el tiempo | They are working today. | 🧠 Ellos están trabajando hoy. |
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Have auxiliary
Have is an auxiliary when it forms perfect tenses with a past participle. Perfect aspect connects a time to a result or experience, often showing something completed before another time. Have changes form for the subject and tense, while the main verb uses the past participle.
Have es un auxiliar cuando forma tiempos perfectos con un participio pasado. El aspecto perfecto conecta un tiempo con un resultado o experiencia, a menudo mostrando algo que se completa antes de otro tiempo. Have cambia de forma según el sujeto y el tiempo, mientras que el verbo principal utiliza el participio pasado.
Rule | 🇪🇸 Español Regla | Example | 🇪🇸 Español Ejemplo |
|---|---|---|---|
| Have + past participle forms the perfect aspect | 🧠 Have + past participle forma el aspecto perfecto | I have finished my work. | 🧠 I have finished my work. |
| Had marks the past perfect for an earlier past time | 🧠 Had marca el pasado perfecto para un tiempo pasado anterior | She had left before noon. | 🧠 She had left before noon. |
| Perfect aspect can express experience up to now | 🧠 El aspecto perfecto puede expresar experiencia hasta ahora | They have visited Paris. | 🧠 They have visited Paris. |
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Do auxiliary
Do is an auxiliary used to form negatives and questions in simple present and simple past when there is no other auxiliary. It also appears in short answers and can add emphasis in affirmative statements. When do is auxiliary, the main verb stays in the base form.
Do es un auxiliar utilizado para formar negaciones y preguntas en el presente simple y el pasado simple cuando no hay otro auxiliar. También aparece en respuestas cortas y puede añadir énfasis en oraciones afirmativas. Cuando do es auxiliar, el verbo principal permanece en la forma base.
Rule | 🇪🇸 Español Regla | Example | 🇪🇸 Español Ejemplo |
|---|---|---|---|
| Use do to make negatives in simple present or past | 🧠 Usa do para hacer negaciones en presente simple o pasado | He does not like coffee. | 🧠 Él no le gusta el café. |
| Use do to make questions in simple present or past | 🧠 Usa do para hacer preguntas en presente simple o pasado | Do you work here? | 🧠 ¿Trabajas aquí? |
| Use do for emphasis in affirmative statements | 🧠 Usa do para énfasis en oraciones afirmativas | I do want to help. | 🧠 Realmente quiero ayudar. |
| After do, the main verb stays in the base form | 🧠 Después de do, el verbo principal permanece en la forma base | She did not go yesterday. | 🧠 Ella no fue ayer. |
Opción múltiple
Which sentence uses do as an auxiliary to make a negative in the simple present?
Modal auxiliaries
Modal auxiliaries add meanings like ability, possibility, permission, advice, and obligation. Common modals include can, could, may, might, must, shall, should, will, would, and ought to. Modals do not take -s, do not use do-support, and are followed by the base form of the main verb.
Los auxiliares modales añaden significados como habilidad, posibilidad, permiso, consejo y obligación. Los modales comunes incluyen can, could, may, might, must, shall, should, will, would y ought to. Los modales no llevan -s, no usan do-support y van seguidos de la forma base del verbo principal.
Rule | 🇪🇸 Español Regla | Example | 🇪🇸 Español Ejemplo |
|---|---|---|---|
| Modals are followed by the base verb | 🧠 Los modales son seguidos por el verbo base | She can swim. | 🧠 She can swim. |
| Modals do not change for third person singular | 🧠 Los modales no cambian para la tercera persona del singular | He can drive. | 🧠 He can drive. |
| Negatives and questions use the modal itself, not do | 🧠 Las negaciones y preguntas usan el modal en sí, no do | Can you help? | 🧠 Can you help? |
| Modals express meanings beyond time, such as obligation or possibility | 🧠 Los modales expresan significados más allá del tiempo, como obligación o posibilidad | You must stop. | 🧠 You must stop. |
Opción múltiple
Choose the correct sentence that shows a modal followed directly by the base verb:
Auxiliary order
When multiple auxiliaries appear together, English follows a common sequence. Modals come first, then perfect have, then continuous or passive be, then the main verb. Each auxiliary determines the form of the next verb, so correct order helps keep meaning clear.
Cuando varios auxiliares aparecen juntos, el inglés sigue una secuencia común. Los modales van primero, luego have en perfecto, luego be en forma continua o pasiva, y luego el verbo principal. Cada auxiliar determina la forma del siguiente verbo, por lo que un orden correcto ayuda a mantener el significado claro.
Rule | 🇪🇸 Español Regla | Example | 🇪🇸 Español Ejemplo |
|---|---|---|---|
| Modal + have + past participle | 🧠 Modal + have + past participle | She might have missed the call. | 🧠 She might have missed the call. |
| Modal + be + -ing | 🧠 Modal + be + -ing | They will be waiting. | 🧠 They will be waiting. |
| Modal + have + been + -ing | 🧠 Modal + have + been + -ing | I would have been working. | 🧠 I would have been working. |
| Modal + have + been + past participle for passive perfect | 🧠 Modal + have + been + past participle for passive perfect | The files may have been deleted. | 🧠 The files may have been deleted. |
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Questions
Auxiliaries help form questions by moving to the beginning of the clause. If there is an auxiliary already, it inverts with the subject. If there is no auxiliary, do is added, and the main verb stays in the base form.
Los auxiliares ayudan a formar preguntas moviéndose al inicio de la oración. Si ya hay un auxiliar, éste invierte con el sujeto. Si no hay auxiliar, se añade do, y el verbo principal permanece en su forma base.
Rule | 🇪🇸 Español Regla | Example | 🇪🇸 Español Ejemplo |
|---|---|---|---|
| If an auxiliary exists, invert auxiliary and subject | 🧠 Si existe un auxiliar, invierte el auxiliar y el sujeto | Are you ready? | 🧠 ¿Estás listo? |
| With have or modals, invert the auxiliary | 🧠 Con have o modales, invierte el auxiliar | Have they arrived? | 🧠 ¿Han llegado? |
| If no auxiliary exists, add do and use base verb | 🧠 Si no existe auxiliar, añade do y usa el verbo base | Did she call you? | 🧠 ¿Ella te llamó? |
Negatives
Auxiliaries create negatives by adding not after the auxiliary. This includes be, have, do, and modals. If there is no auxiliary in a simple present or past statement, do is added and the main verb stays in the base form.
Los auxiliares crean negaciones añadiendo not después del auxiliar. Esto incluye be, have, do y modales. Si no hay auxiliar en una afirmación simple en presente o pasado, se añade do y el verbo principal permanece en la forma base.
Rule | 🇪🇸 Español Regla | Example | 🇪🇸 Español Ejemplo |
|---|---|---|---|
| Place not after the auxiliary | 🧠 Coloca not después del auxiliar | She is not coming. | 🧠 Ella no está viniendo. |
| Modals take not directly | 🧠 Los modales toman not directamente | You should not worry. | 🧠 No deberías preocuparte. |
| Add do if there is no auxiliary | 🧠 Añade do si no hay auxiliar | We do not know. | 🧠 No sabemos. |
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Contractions
Auxiliaries often contract in everyday English, especially with pronouns. Not also contracts with many auxiliaries. Contractions are common in speech and informal writing, while full forms are more formal or used for emphasis and clarity.
Los auxiliares a menudo se contraen en el inglés cotidiano, especialmente con pronombres. 'Not' también se contrae con muchos auxiliares. Las contracciones son comunes en el habla y en la escritura informal, mientras que las formas completas son más formales o se usan para énfasis y claridad.
Word/Phrase | 🇪🇸 Español Palabra/Frase | Definition | 🇪🇸 Español Definición | Example | 🇪🇸 Español Ejemplo |
|---|---|---|---|---|---|
| I am → I’m | 🧠 I am → I’m | Be contracted with the subject | 🧠 Be contraído con el sujeto | I’m late. | 🧠 I’m tarde. |
| She is → She’s | 🧠 She is → She’s | Be contracted with the subject | 🧠 Be contraído con el sujeto | She’s working. | 🧠 She’s trabajando. |
| They have → They’ve | 🧠 They have → They’ve | Have contracted with the subject | 🧠 Have contraído con el sujeto | They’ve finished. | 🧠 They’ve finished. |
| do not → don’t | 🧠 do not → don’t | Negative contraction with do | 🧠 Contracción negativa con do | I don’t agree. | 🧠 I don’t agree. |
| will not → won’t | 🧠 will not → won’t | Irregular negative contraction with will | 🧠 Contracción negativa irregular con will | He won’t come. | 🧠 He won’t come. |
Auxiliary vs main
Many auxiliary verbs can also act as main verbs. As auxiliaries, they support another verb and often help grammar like tense, questions, or negatives. As main verbs, they carry the core meaning and can appear alone, often with a different structure.
Muchos verbos auxiliares también pueden actuar como verbos principales. Como auxiliares, apoyan a otro verbo y ayudan con la gramática como tiempo, preguntas o negaciones. Como verbos principales, llevan el significado central y pueden aparecer solos, a menudo con una estructura diferente.
Rule | 🇪🇸 Español Regla | Example | 🇪🇸 Español Ejemplo |
|---|---|---|---|
| Be can be a main verb for identity or state | 🧠 Be can be a main verb for identity or state | She is a teacher. | 🧠 She is a teacher. |
| Have can be a main verb for possession or experience | 🧠 Have can be a main verb for possession or experience | They have a car. | 🧠 They have a car. |
| Do can be a main verb for actions or tasks | 🧠 Do can be a main verb for actions or tasks | I do my homework. | 🧠 I do my homework. |
| As auxiliaries, these verbs combine with another verb form | 🧠 As auxiliaries, these verbs combine with another verb form | They have eaten already. | 🧠 They have eaten already. |
Key takeaway
Auxiliary verbs are be, have, do, and the modals, and they work with a main verb to build meaning and grammar. They form continuous and passive structures with be, perfect structures with have, and questions and negatives with do when needed. Modals add meanings like ability and obligation and are followed by the base verb. Recognizing auxiliaries helps you form correct questions, negatives, and multi-verb verb phrases.
Los verbos auxiliares son be, have, do y los modales, y trabajan con un verbo principal para construir significado y gramática. Forman estructuras continuas y pasivas con be, estructuras perfectas con have, y preguntas y negaciones con do cuando es necesario. Los modales añaden significados como habilidad y obligación y van seguidos del verbo base. Reconocer los auxiliares te ayuda a formar preguntas, negaciones y frases verbales con múltiples verbos de manera correcta.
