Conditional Sentences

 There are four types of conditional sentences.

The past is important. It’s where we’re all from. We need to use past tense to describe most of our
personal experiences, as well as things that have happened to other people. In fact, there’s an entire
academic field devoted to studying the past: history. But language about past events is not just found in
history texts.

There are four past tenses, and nine total ways to use the past tense. Understanding these tenses and
uses can really help you with academic reading, listening, speaking, and writing. Below, I’ll go over each
past tense and its uses, with examples.
Simple Past
Form: Take the base verb and change the word form to the past tense form. Usually this means adding
/ed/ to the end of the word. However, much like simple present tense, there are a lot of irregular
verbs with different past tense forms.
Uses:
Use 1: Actions completed in the past:
EXAMPLES: The scientists conducted an experiment. They thought the experiment would prove their
theory.
Past Continuous
Form: The past form of “to be” (was, were) + verb + ing
Uses:
Use 1: Describing a past action that hasn’t been completed yet
EXAMPLES: I was trying to fix the car this morning, but I’m not done with the repairs yet. At 11pm,
I was still working on my homework.
Use 2:Describing a past action that was interrupted by another action
EXAMPLES: The radio station was broadcasting music when the music was interrupted by an important
announcement. I was trying to sleep when I heard a knock at my door.
Use 3: When describing two past events that took place at the same time, this tense is used to describe
the longer of the two events. (You can use simple past for the shorter event. You can also use past
perfect for the shorter event; see Use 2 of past perfect later in this post for an example.)
EXAMPLES: Marco Polo contacted Chinese merchants and leaders while he was travelling the world. She
burned herself while she was cooking dinner.
Use 4: Describing a past action that took place in a specific time period and may have continued
afterward
EXAMPLES: The science team was conducting research as recently as last month. Many students were
feeling depressed in in February. (Note: In sentences like this, the use of past continuous implies that the
activity may have continued after the time period mentioned in the sentence. It also may have stopped.
In other words, maybe the team of scientists in the first example are still doing research, or maybe they
are not. And maybe the students kept feeling depressed after February, or maybe they felt better by
March.)
Past Perfect
Form: had+ past form of a verb
Uses:
Use 1: When describing a series of actions, use past perfect to describe the action that happened first
EXAMPLES: I had gone home; then I read a book and fell asleep. The lawyers hadslowly worked toward
an agreement that was acceptable for everyone; then they printed the agreement and gave it to their
clients.
Use 2: When you are describing two past actions that take place at the same time, you can use past
perfect tense to describe the shorter action. The longer action can be described using simple past tense
or past continuous tense. See Use 3 of past continuous earlier in this post.
EXAMPLES: Marco Polo had contacted Chinese merchants and leaders while he traveled the world.
She had burned herself while she was cooking dinner. (While these two sentences use slightly different
tenses than the examples in Use 3 of past continuous, they have the exact same meaning as the earlier
past continuous examples.)
Use 3: Describing a past action that was finished in a specific time period:
EXAMPLES: The science team had conducted research as recently as last month. Many students had
felt depressed in in February. (Note that these example sentences are almost identical to the example
sentences for Use 4 of past continuous earlier in this past tense tutorial. The only difference is that they
use past perfect verb tense instead. But this small difference changes the meaning of the sentence. In the
past continuous example, the scientists may or may not have continued their research after last month,
and the students may or may not have kept feeling depressed after February. However, in these new
sentences with past perfect verbs, the scientists definitely did not continue their research after last
month, and the students definitely stopped being depressed after February.)
Past Perfect Continuous
Form: had + been + verb + ing
Uses:
Use 1: Describing an action that began further in the past than other actions, but overlaps with actions
that began later.
This use is a little complicated, so read my explanation carefully: Suppose you want to describe a series of
actions. Now suppose there’s one action that started before the other actions, but continued even after
the next action began. For example, imagine you began to eat dinner, and then while you were eating,
you began to think about what you would do on the weekend. You would use the past perfect continuous
to describe the action that started earlier (eating dinner) but happened partly at the same time as an
action that started later (thinking about what you would do on the weekend). The action that started
later would be described using simple past tense. So the sentence would look like this: I had been eating
dinner when I thought about what I would do on the weekend.
EXAMPLES: Chiang Kai Shek had been leading his political followers for many years when he and his
followers fled from China to Taiwan. She said she had been working in a hospital when World War II
started, and she worked there for many more years.
You may notice that past tense is a little more complicated than present tense. If you have any
questions about the explanations and examples above, don’t be shy. Feel free to post your question as a
comment, and I can answer it. You can also ask me questions through my Google + account, linked
under “About the Author” below.
Use 2: Describing an a past action that was interrupted or stopped by another action. (Note that this use
serves the same purpose as Use 2 of past continuous, mentioned earlier in this article.
EXAMPLES: He had been driving in his car for more than two hours, but then he stopped to rest. She
said she had been teaching at Harvard, but she retired.
Use 3: Describing an action that caused a later action.
EXAMPLES: The water had been running from the faucet, and it got all over the floor. His muscles had
become large, because he had been lifting weights.