Continuous Tenses

                                                        Present continuous   

Affirmative
s.sub.+is+m.v.+ing+o.                                                          He is writing a letter.
p.sub.+are+m.v.+ing+o.                                                       We are writing letters.
Negative
s.sub.+is+not+m.v.+ing+o.                                                   He is not writing a letter.
p.sub.+are+not+m.v.+ing+o.                                                We are not writing letters
Interrogative
Is+s.sub.+m.v.+ing+o.+?                                                        Is he writing a letter?
Are+p.sub.+m.v.+ing+o+?                                                       Are we writing letters?
Double Interrogative
Q.word+is+s.sub.+m.v.+ing+o.+?                                           When is he writing a letter?
Q.word+are+p.sub.+m.v.+ing+o+?                                        Why do we writing letters?

                                                        Past continuous   

Affirmative
s.sub.+was+m.v.+ing+o.                                                          He was writing a letter.
p.sub.+were+m.v.+ing+o.                                                       We were writing letters.
Negative
s.sub.+was+not+m.v.+ing+o.                                                   He was not writing a letter.
p.sub.+were+not+m.v.+ing+o.                                                We were not writing letters
Interrogative
was+s.sub.+m.v.+ing+o.+?                                                        Was he writing a letter?
were+p.sub.+m.v.+ing+o+?                                                       Were we writing letters?
Double Interrogative
Q.word+was+s.sub.+m.v.+ing+o.+?                                           When was he writing a letter?
Q.word+were+p.sub.+m.v.+ing+o+?                                        Why were we writing letters?

                                                        Future continuous   

Affirmative
s.sub.+will/shall+be+m.v.+ing+o.                                                He will be writing a letter.
p.sub.+will/shall+be+m.v.+ing+o.                                                We shall be writing letters.
Negative
s.sub.+will/shall+not+be+m.v.+ing+o.                                          He will not be writing a letter.
p.sub.+will/shall+not+be+m.v.+ing+o.                                          We shall not be writing letters
Interrogative
Will/Shall+s.sub.+be+m.v.+ing+o.+?                                            Will he be writing a letter?
Will/Shall+p.sub.+be+m.v.+ing+o+?                                             Shall we be writing letters?
Double Interrogative
Q.word+will/shalls+s.sub.+be+ m.v.+ing+o.+?                             When will he be writing a letter?
Q.word+will/shall+p.sub.+be+1m.v.+ing+o+?                              Why shall we be writing letters?