The present continuous tense is an important tense in English. It shows actions that are happening right now. For example, when we see someone running, we say they are running. The present continuous emphasizes that the action is in progress at this moment.
The present continuous tense has a simple structure. We use the subject, followed by am, is, or are, and then add -ing to the main verb. For example: I am reading, She is singing, They are playing, We are studying.
Which helping verb do we use? It depends on the subject. With 'I', we use 'am'. With 'he', 'she', or 'it', we use 'is'. With 'you', 'we', or 'they', we use 'are'. This is the same pattern as the verb 'to be'.
How do we add -ing to verbs? There are three main rules. First, for most verbs, just add -ing. Second, if a verb ends in silent -e, remove the -e and add -ing. Third, for short verbs with one vowel, double the last letter and add -ing.
Let's practice with some examples. First, 'I blank watch TV now.' The answer is 'I am watching TV now.' Second, 'She blank cook dinner.' The answer is 'She is cooking dinner.' Third, 'They blank play football.' The answer is 'They are playing football.' Remember to use am, is, or are with the -ing form of the verb to show actions happening now.
现在进行时的结构很简单。我们需要三个部分：主语、be动词和动词的ing形式。就像搭积木一样，把这三个部分组合起来。比如'I'加上'am'再加上'reading'，就组成了完整的句子'I am reading'。
be动词会根据主语的不同而变化。当主语是I时，我们用am。当主语是he、she或it时，我们用is。当主语是you、we或they时，我们用are。让我们看看每个人称对应的be动词。
动词变成ing形式有四种主要规则。第一种是直接加ing，比如play变成playing。第二种是去掉末尾的e再加ing，比如make变成making。第三种是双写末尾字母再加ing，比如run变成running。第四种是把ie变成y再加ing，比如lie变成lying。