An "if" sentence is one in which the occurrence of one event depends on the other event happening. When I say, "We will go to the beach today if it is sunny", I am saying that the "going to the beach" depends on "it being sunny". In this situation, the sunnny day is the "trigger" event which makes the trip happen. This "trigger" event is expressed in the part of the sentence which begins with the word "if". There are some sentences in which we find the word "if" that are NOT true "if" sentences. For example, when we say, "I don't know IF John is coming soon", we are using the word "if", but we are not using the pattern that we are studying here. There is no event that depends on another. John's coming doesn't trigger my knowing. Some books on grammar call the pattern that we are studying "conditional" sentences. We can emphasize the relationship between the two events even more strongly if we add the word "only" in front of the word "if". For example: "We will go to the beach today ONLY IF it is sunny."

There are three basic patterns for "if" sentences, both in English and in Spanish. They correspond to the time frames when the events take place. We could be speaking about the future, the present, or the past:

• We will wash the car if John buys the detergent.
• We would wash the car if John bought the detergent.
• We would have washed the car if John had bought the detergent.

Notice that in the first sentence we are talking about the future. We are telling what we WILL do if the "trigger" event takes place.

In the second sentence we are speaking about the present. We are saying what we would be doing if the "trigger" event were true, but since it isn't true, we are not doing it. Some books call this "contrary to fact" since it describes an unreal event that isn't happening.

Now let's look at the third example. In this case we are talking about the past. We are talking about an event which is "contrary to fact", since it didn't really happen. We can see that the second and third patterns are different in an important way from the first one. In the second and the third cases, we know that what we are saying "would" happen, doesn't in fact happen. We are not talking about real events.

Let's compare the English and the Spanish sentences.

We will wash the car if John buys the detergent.
Nosotros lavaremos el carro si Juan compra el detergente.

In the first part of the sentence we use the "will" form in Spanish, just like we do in English.

We can see that this first pattern works the same in Spanish as it does in English. Let's state this pattern clearly so that we remember it. In the first pattern we have the following:

PATTERN #1: "will do".........."IF"..........(regular present)

In the second pattern we see some similarities with English also. Let's look at the second pattern.

We would wash the car if John bought the detergent.
Nosotros lavaríamos el carro si Juan __________ el detergente.

Let's compare the first part of the sentences in English and in Spanish. You can see that we use the "would" form of the verb in both English and Spanish for the first part of the sentence. Remember that this is the part of the sentence that expresses the event that depends on the "trigger".

In English, to express something which isn't true in the present time, we use the past tense, which in this case is "bought". This contrast between the past tense form and the present tense meaning is what English uses to express the "contrary to fact" idea. We can see this in many cases, such as, "if I had the money" (notice that we mean "now", not in the past, even though we are using the past tense). Spanish does the same thing. To express a "contrary to fact" idea in the present, we are going to use a past tense form of the verb. In Spanish, however, there is one more thing that we have to keep in mind. Remember that there are several past tense forms of the verb in Spanish. We have the preterite, the imperfect, and also the past subjunctive verb form. Which of these are we going to use? Well, let's think for a moment about sentence in which the ideas of doubt or disbelief are expressed. You should remember that when you express doubt or disbelief you must change the verb form. Notice the examples:

• Yo creo que el libro está en la biblioteca.
• Yo no creo que el libro esté en la biblioteca.

We must change the verb to the subjunctive when we express doubt or disbelief. When we say, "if John bought" we are indicating that we don't believe that he has done it. Therefore, in pattern #2, we have to use the past subjunctive in the part of the sentence that begins with the word "if", which expresses the "trigger" event. We can now fill in the blank for pattern #2.

Nosotros lavaríamos el carro si Juan comprara el detergente.

Some people use the word "would" in the second part of the sentence in English to emphasize this "contrary to fact" idea. This isn't considered to be perfect English, but it does make the point.

• We would wash the car if John would buy the detergent.

The "would" part of the sentence is used ONLY in the "result" part of the sentence, not in the "trigger" part. We can now state the pattern clearly for the second type of "if" sentence.

PATTERN #2: "would do".........."IF"..........(past subjunctive)

Now let's take a look at the third pattern.

• Nosotros habríamos lavado el carro si Juan hubiera comprado el detergente.
  We would have washed the car if John had bought the detergent.

You can see that this third pattern is also "contrary to fact". We know that John didn't buy the detergent and that we didn't wash the car. We are just speaking about what "would have happened...", but didn't in fact happen. Once again we have to use the subjunctive in the part of the sentence that expresses the "trigger" event, because it's not true. You can see that in the first part of the sentence we are using the "would" form of "have" and in the second part of the sentence we are using the past subjunctive form of "have". Pattern #3 is just like pattern #2 except that it is in the past and we use the corresponding forms of the verb "haber" followed by the "-do" form of the verb which expresses the event. You might remember that this form of the verb which ends in "-do" is called the participle. Let's put this third pattern in a general form like we did for the first two patterns.

PATTERN #3: "would have done".........."IF"..........(past perfect subjunctive)

Remember that the past perfect subjunctive is merely the past subjunctive of "haber" plus the participle of the main verb that expresses the event. Let's put all of the three possible "if" sentence patterns together now so that we can get a clear picture of them in our minds.

PATTERN #1: "will do"........"IF"......(regular present)
PATTERN #2: "would do"........"IF"......(past subjunctive)
PATTERN #3: "would have done"....."IF".....(past perfect subjunctive)

You can see that these three patterns aren't really that much different from the ones that we use in English. The main thing for you to remember is that in pattern #2 and in pattern #3 the events which "trigger" the other event aren't true. Just as we have seen with sentences expressing doubt, disbelief and denial, we have to use the subjunctive form of the verb to express unreal events.

Use of "if" Clauses

Fill-in-the-Blank Quizzes

"if" Clauses 1

"if" Clauses 2

"if" Clauses 3

Related Topics

Use of Past Perfect Subjunctive

Conditional Clauses