Now that you are studying English at a high level, you need to be able to talk about the language itself.
One of the biggest areas of confusion for students is the difference between the past tense and the present perfect.
The past tense is indicated by use of the past tense marker, represented here by V(d).
Here are some examples of regular verbs and their past tense forms.
So as you can see, for regular verbs, the past tense form is indicated by the addition of an "ed" at the end of the verb.
However, some of the most common verbs in English are irregular, so it's important to learn them.
Here are some examples.
eat ate
drink drank
get got
take took
come came
be was/were
Altogether, there are over 200 irregular verbs in normal use. 不规则的；无规律的
Many people think that the past tense form only indicates past time.
However, that is only one of the possible meanings.
The past tense form is also used to express something that is unlikely or imaginary, from the speaker's point of view.
Here's an example: "He wishes he had a car."
The fact is that he doesn't have a car, so the use of "had" indicates that it isn't real: it's imaginary.
If he had a car, he could drive us to school.
Again, he doesn't have a car, so he can't drive us to school.
This condition expresses something that isn't a fact.
It's a counterfactual condition, which means it goes against what we know or believe.
Look at these two sentences.
"If she waits another week, she can save money..."
"If she waited another week, she could save money because there's going to be a sale."
Both sentences are correct, but there is a difference in meaning.
In the top sentence, the condition that she waits, is more likely from the speaker's point of view.
In the bottem sentence, the speaker thinks it's less likely that she is going to wait.
If that flight left a few minutes later, we could take the next shuttle bus.穿梭班机、公共汽车等
I wish we didn't have to run, but if we don't hurry, we'll miss the next bus.