Grammar: Present Simple, Present continuous and perfect.

The most typical use of English grammar in sentences is present simple. However, this tense cannot be always used for the different issues we want to communicate. Present simple is used:

• For Statements that are always TRUE or that happen regularly. For instance, we use present simple when we talk about something we do in our daily life. Ex: she usually has cereal for breakfast.
• When we use ASI (auxiliary verb, subject, infinitive) or QUASI (question word, auxiliary verb, subject, infinitive), to help you with order in questions. Ex: what does she want for Christmas? 
• When we use some adverbs of frequency, in order to explain what we normally do. Ex: I usually go to school by bus. 

When we talk about present simple, we have to bear in mind that the third person singular changes. It means, when we have to conjugate the third person singular of verb we have to add a -s at the end of the verbal form. Nevertheless there are few verbs in which the third person implies some changes in the verbal form. Ex: Lives, studies, watches.

On the other hand we have another present tense, which is used for actions in progress at the time of speaking. The structure of this tense is: BE+VERB+-ING. For instance: I am waiting for a friend. 

This present tense is commonly known as PRESENT CONTINUOUS and it can also used for future arrangements that are near. Ex: I am going to the cafe next weekend.

In this especific tense, there are also some spelling rules in verbal forms. ex: Living, studying, getting. 

Comparing these two grammatical tenses, we realize that there are other different kinds of verb.

• Action verbs. This kind of verbs describe action, and they can be used in the present simple or continuous. Ex: make, cook: I'm making pasta.
• Verbs which describe states or feelings(not actions) are not normally used in the present continuous. Ex: like,want, be: I want a cake.
• Common non-action verbs. Among these verbs are: agree, believe, depend, seem,suppose. Ex. I agree with you.

Despite of these verbs, there are a few verbs that have an action and non-action meaning. The most common one is have. Ex: I have big flat (possession, non-action)/ I can't talk now. I'm having lunch(an activity, action). 

Talking about present tense, we have also to mention the present perfect (Simple and Continuous)

• Present perfect simple: HAVE/HAS+PAST PARTICIPLE. We use present perfect when there is a connection between the past and the present. We often use ever and never when we ask or talk about last experiences. They go before the main verb. We can also use just and already before the main verb in affirmative sentences,and yet goes at the end of the phrase in negative and interrogative sentences. Another expressions we can use with this grammatical tense are: for + a period of time (I have been there for two weeks) or since with a pint of time (I have been there since 1950) 
• Present perfect continuous. HAVE/HAS BEEN+VERB+ING. We use the present perfect continuous for unfinished actions: He has been working here since April, or for recent continuous actions: I have been cutting onions.

I hope you would learn and enjoy with this entry.