Simple Past, Simple Present, Present Continuous and Past Continuous.

Simple Present
  The simple present can be used to express:  



1 - a habitual action, that is, at what we always do:
 I always leave home at 7:00. (I always leave home at 7am).
 Generally They have lunch at the shopping mall. (They usually have lunch at the mall).
 I never work on Sundays. (I never work on Sundays).

2 - a universal truth:
 Babies cry. (Baby crying).
 Dogs bark. (Dogs barking).
 Birds sing. (Birds sing).

 The "do" and "does" are the two assistants of this simple, and they should always be used in negative and interrogative sentences, as shown below:

negative                                            interrogative
I do not accept / I do not ...                 Do I ...?
You's not / do not you ...                      Do you ...?
He does not / he does not ....             Does he ...?
She does not / she does not ...          Does she ...?
It does not / does not it ...                    Does it ...?
We do not / we do not ...                     Do we ...?
You's not / do not you ...                      Do you ...?
They's not / they do not ...                   Do They ...?


Simple Past
The verbs in the PAST SIMPLE is used to indicate an actioncompleted fully in the past or an occurrence of habitual actions in the past.
The helper used for negative and interrogative sentences is did. 
Its structure is as follows:

· To claim: SUBJECT + VERB INFINITIVE (without "to") + ED
Examples: (to love)

 I loved
 He / She / It loved
 You loved

· To Denial: AUXILIARY + SUBJECT + VERB + NOT INFINITIVE(without "to")
Example: (to love)

 I did not love
 He / She / It didi not love
 You did love

 - You can replace fired by their contracted form, did not.

· To mark: AUXILIARY + SUBJECT + VERB INFINITIVE (without"to")
Examples: (to love)

 Did I love?
 Did you love?
 Did he / she / it love? 




Present Continuous
This continued to be used to express a situation that is in progress,ie, an action that is still happening. All our "walk", "endo" and "going"verbs in Portuguese should be replaced in English by "ing."
The construction of this second continuous should be given the form:

Subject + verb to be + verb with "ing" + add
She is studying English now. (She is studying English right now).
For the negative, just add the "not" after the verb "to be" (am, is are). 

To develop an interrogative sentence is necessary to put the verb "to be" the beginning of the sentence:
Mariane is talking to Bob? 


Past Continuous
The past continuous is used to refer to a situation that was in progress at any given time in the past. The construction of the pastcontinuous be given according to the form:

Subject + verb "to be" in the past (was / Were) + verb with "ing" +complement.She was working yesterday night. 

For the negative, just add the "not" after the past tense "to be" (Was /Were):
They Were not studying when i arrived home. 

To develop an interrogative sentence is necessary to put the past of the verb "to be" (Was / Were) at the beginning of the sentence:
Was Lisa copying Marianne's exercises?