The first part tells us what the action is. This is the "stem".

The second part gives us other kinds of information about the verb. For example, the "a" or "e" in the middle tell us which of the two patterns to follow in using this particular verb. The vowel tells us which category the verb belongs to.

The last part of the verb normally tells us who is doing the action. It makes the verb match the subject. You should remember that when "I" do something, the verb will have an "o" in the last place. If "we" do something, you will find "mos" in the last place.

There are some cases, however, when the third place in the verb is used for a different purpose. That is what we are going to study in this lesson. A verb can be a single word, or we can have a verb phrase which is made up of a string of words. When this happens, there is a definite pattern which is followed. Look at the following example.

Nosotros necesitamos los libros.
Nosotros necesitamos estudiar.

In the first case, we need THINGS (books). In the second case, we need TO DO SOMETHING. The action that we need to do is expressed by a verb. By combining "need" with "to study" we create a VERB PHRASE. The first verb in this two word string should be familiar to you now. We would divide it up like this.

STEM    CATEGORY    MATCH 

necesit -   a  -    mos 

Now, if we take the second verb in the phrase, "estudiar", we find that the last part of the verb has an "r" instead of an ending which would normally match the subject. This "r" is like saying "to" in English, such as in "to study". The indicator for the INFINITIVE in English is the word "to" placed in front of the verb. In Spanish, we indicate the INFINITIVE by placing the letter "r" in the last slot of the verb itself. Now if you look at the sentence, "Nosotros necesitamos estudiar" you can see that what this really is saying is, "We need to study". There isn't a separate word "to" in Spanish for the infinitive. We simply place the letter "r" on the end of the verb, instead of one of the endings that we normally use to make it match the subject. We could analyze it like this.

STEM      CATEGORY       MATCH
  
estudi  -    a      -      r 

Now, let's see how the infinitive form of "study" combines with other forms of "need".

Yo necesito estudiar.
Maria necesita estudiar.
Los chicos necesitan estudiar.

You probably noticed that while the verb "need" changes its ending to match the subject, "I", "Mary", and "the boys", the infinitive does not change. It stays the same in all cases. It never varies.

There are other verbs that we can combine with infinitives in order to create a verb phrase. One of them which is used very frequently is the verb "go". We normally use this verb to express movement from one place to another, but we can also use it to express the idea that an action is going to happen in the future. Let's take a look at how we would say, "we are going to study".

Nosotros vamos a estudiar.

Did you remember that we nearly always use the word "a" which means "to" after the verb "go"? If you did, you might notice that it appears to someone who speaks English that we are saying "to" twice in the sentence. The word "a" after "go" translates as "to", and the letter "r" on the end of the infinitive is translated as "to". It would sound like we said, "We are going to to go". The important thing to remember is that this really doesn't matter. We know how to say it in English, and we would not put the word "to" in twice if we were translating the Spanish sentence into English. However, you must view the patters of Spanish from the inside of the language, not from the point of view of English. Remember, most people who speak Spanish do NOT speak English and don't have any idea that English speakers seem to find the word "to" occurring twice in the Spanish sentence.

You may have also noticed that we did not have a separate word for "am" in the "am going" part of the sentence. We just said "nosotros vamos" or "we go". The words "am", "is", and "are" just don't appear with the word "going". Frequently you can not translate word for word from one language to another. You have to follow the language's own internal patterns if you are going to speak correctly. What is important for you to remember is that and "r" is used on the end of a verb when you want to say, "to do something" and that after the word "go" we nearly always will find the word "a". These are patterns which are normal in Spanish.

Let's do a few examples in which we use "go" with the infinitive of another verb to express an action that is going to take place in the future.

How would we say, "John is going to read the book"?

How would we say, "I am going to read the book"?

How would we say, "We are going to read the book"?

Another use of the infinitive (the "...R" form) is with the verb "have" to express an obligation to do something. We do this in English also. If I say, "she has to study", I am not talking about possession. Normally the word "have" (or "has") does express possession, such as in, "We have the money", but in this case we are not claiming that she "possesses" something. We are saying that there is an OBLIGATION for her to DO something. In Spanish we would say it like this:

Ella tiene que estudiar

Did you notice the word "que" appears in the sentence. We know from earlier lessons that the word "que" means "that" normally when we use it in Spanish. In this case, however, we do not translate "que" as "that". The word "que" is used in Spanish with the word "have" to show that we are not talking about possession, but rather obligation. It wouldn't sound correct in English to insert the word "that" in this sentence, but in Spanish it doesn't sound right to people who are native speakers of the language to leave out the word "que" when we are speaking of the obligation to do something.