There are two past tense forms in Spanish: the imperfect and the preterite. The "imperfect" is the primary past tense form that we need to learn. We have a stem (the first part), and "infix" (or middle part), and the ending (which matches the subject). Let's take a look at a present tense form and compare it with the past imperfect form of the verb.

• Los chicos hablan.

Notice that the first part of the verb "hablan" is "habl". That is the stem. The "a" in the middle is the infix. It identifies the verb as an "a" category verb. If we used an "e" verb, such as "comer", the infix would be "e". The infix matches the category of the verb and determines which pattern we are going to follow in the other tense (time forms--present or past) of the verb. We know that we have to follow the "a" pattern for this verb. The "n" at the end of the verb matches the subject "los chicos" which is the same as "ellos". We have learned previously that when a verb means "they do something", it must end in the letter "n". The "n" matches "ellos", the subject of this sentence.

You should notice that English also makes changes to the verb in order to change the time limits of the action. Sometime we add other words, such as "was" along with an addition of and ending "-ing" such as "He was working". Sometimes we just add different words in combinations, such as "He used to work". Then at other times we add a suffix to the end of the verb which indicates that the action happened in the past. Let's continue to use the verb "work" which is a regular verb in English and demonstrates the patterns that we have available. Examples of this would be:

• He was working.
• He used to work.
• He worked.

Of course there are other verbs in English which are irregular and these can behave in a different manner. In the case of the verb "speak" we can't just add "-ed" to the end of the plain verb to get the past. Look at the following examples.

• He was speaking.
• He used to speak.
• He spoke.

Notice that we can't add "-ed" and say, "He speaked".

In order to form the past imperfect tense of the verb "hablan", we are going to change the infix. The infix tells us whether we are speaking about facts or feelings (which may or may not be true), but it also tells us if we are speaking of the present or the past. In the case of the past tense, we are going to change the infix "a" to "aba". Therefore we are going to have the following sentence in the past imperfect tense.

Los chicos hablaban.

The stem of the verb has not changed. It is still "habl". The "n" on the end of the verb is the same also. We are still saying that "ellos" (they) are involved in some action. What has changed is that the infix "a" has changed to "aba", and that change tells us that the action is not happening now, but rather it was happening in the past. In English we might translate this in different ways.

• The boys were talking.
• The boys used to talk.
• The boys talked.

Let's see how the complete pattern of the imperfect past of the verb "hablar" looks in Spanish.

yo hablaba       nosotros hablábamos
tú hablabas      ellos hablaban
él hablaba

In the case of "hablábamos", we add an accent mark. That's because the ending "mos" adds another syllable and the rules of Spanish regarding spelling require the written accent mark. Remember that in the form which says that "we were doing something", we have to have a written accent mark on the first "a" of the "aba" infix.

You may have noticed also that there is a small change in the ending of the form of the verb which matches "yo". In the present tense, we added "o" at the end of the verb, and the infix was dropped. In the imperfect past tense, the infix "aba" remains and the "o" is no longer present. In fact, we are going to see as we go along that the "o" which matches "I" is only used in the regular present tense. This follows the same pattern that we learned in the verb forms which were used in sentences that expressed feelings. The form which matches "yo" looks exactly the same as the form which matches "él".

Let's practice changing some present tense sentences into the past, using the past imperfect infix. Look at the following examples:

Yo trabajo en la oficina.

Tú trabajas en la oficina.

Juan trabaja en la oficina.

Nosotros trabajamos en la oficina.

Ellos trabajan en la oficina.

The stem of the verb "work" is "trabaj". That is going to remain the same in all forms. For the past imperfect, since this is an "a" verb, we are going to use the infix "aba". We would get the following:

Yo trabajaba en la oficina.

Tú trabajabas en la oficina.

Juan trabajaba en la oficina.

Nosotros trabajábamos en la oficina.

Ellos trabajaban en la oficina.

The sentences above could be translated as:

I was working (used to work, worked) in the office.

You were working (used to work, worked) in the office.

John was working (used to work, worked) in the office.

We were working (used to work, worked) in the office.

They were working (used to work, worked) in the office.

Now let's take a look at verbs in the "e" category. Remember that the "e" category verbs are going to have an "e" as the infix in the present.

Yo leo. (infix missing because of the "o" ending to match "yo")

Tú leías.

Juan leía.

Nosotros leíamos.

Ellos leían.

The infix for the past imperfect tense of the "e" category verbs is "ía" and in all five forms the letter "i" has a written accent. That is because of another pronunciation/spelling rule of Spanish. The letters "i" and "u" are considered to be what we call "weak vowels". That means that when they are in combination with another vowel, they aren't "strong" enough to make a syllable of their own and the two vowels are included in the same syllable. The "i" ends up being pronounced as the letter "y" would be, and the letter "u" with another vowel would be pronounced as the letter "w" in English, such as in "puedo" which is pronounced like "pwaydoh". For the imperfect infix of "e" verbs, we don't pronounce "yah" but rather we make the "i" a full syllable of its own. This is done by putting a written accent over the "i". It is pronounced like "eeah" (like double "e" in English as in the word "teeth"). Again, the "o" which matched "yo" in the present tense in English has disappeared and we keep the infix. We would translate the above past tense verb forms in Spanish as:

I was reading (used to read, read).

You were reading (used to read, read).

John was reading (used to read, read).

We were reading (used to read, read).

They were reading (used to read, read).

There are a few irregular verbs in the present tense in Spanish, but not many. ONLY the verbs "go", "is" and "see" are irregular in the imperfect past. Here are the irregular past tense forms of these irregular past imperfect verbs forms in Spanish.

For the verb "ir" we might expect "vaba". That is, if we take "va" and change the "a" to "aba" for the imperfect, we would logically get "vaba". However this isn't the case. Just as in English you can't take "go" and add "-ed" to say "goed" in the past tense, in Spanish you have to memorize and exception. For the verb "go" the irregular past imperfect form is "iba". The pattern would look like this:

Yo iba a la iglesia los domingos.

Tú ibas a la iglesia los domingos.

Juan iba a la iglesia los domingos.

Nosotros íbamos a la iglesia los domingos.

Ellos iban a la iglesia los domingos.

You probably noticed that once more, in the nosotros form, we had to add an accent mark on the letter "i" of "íbamos". That is because of the Spanish spelling/pronunciation rules which tell us where we have to write accent marks. We would translate the sentence above as follows:

I was going (was going regularly or used to go habitually) to the church on Sundays.

You were going (were going regularly or used to go habitually) to the church on Sundays.

John was going (was going regularly or used to go habitually) to the church on Sundays.

We were going (were going regularly or used to go habitually) to the church on Sundays.

They were going (were going regularly or used to go habitually) to the church on Sundays.

For the verb "es" we have irregular verbs in the present tense also.

yo soy         - I am
tú eres        - you are
Juan es        - John is
nosotros somos - we are
ellos son     - they are

Remember that this is the form of "is" or "be" that we use to tell what or who someone is, not where someone is. We might use "es" forms for something like the following where we are saying what someone is.

Yo soy un alumno inteligente.

Tú eres un alumno inteligente.

Juan es un alumno inteligente.

Nosotros somos alumnos inteligentes.

Ellos son alumnos inteligentes.

At some point in the future I might look back and say that "I was an intelligent student", etc.

Yo era un alumno inteligente.

Tú eras un alumno inteligente.

Juan era un alumno inteligente.

Nosotros éramos alumnos inteligentes.

Ellos eran alumnos inteligentes.

In English we would translate these sentences in the following way:

I was (used to be) an intelligent student.

You were (used to be) an intelligent student.

John was (used to be) an intelligent student.

We were (used to be) intelligent students.

They were (used to be) intelligent students.

For the verb "see" we would have the following forms in the present:

yo veo

tú ves

Juan ve

nosotros vemos

ellos ven

The past imperfect forms would look like this:

yo veía

tú veías

Juan veía

nosotros veíamos

ellos veían

Notice that the verb "see" is an "e" verb and we are using "-ía" as an infix. The problem here is that the stem is only "v", not "ve" in the present, but in the past imperfect we don't get "vía" but rather "veía". We keep the letter "e" in the stem.

If you check in a standard Spanish grammar verb list, you will find that these three verbs are the only ones which have irregular forms in the imperfect. Here is a table to show you the infix patterns.

fact       feeling 
a          aba  

And for verbs in the "e" category we would have:

fact       feeling 
e          ía