Công thức thì HTTD 

(+) S + am/is/are + Ving 

(-) S + am/is/are + not + Ving 

(?) Am/Is/Are +S +Ving? 

I + am

S số ít, he, she, it + is

S số nhiều, you ,we, they + are

DHNB: now, right now, (!), at present, at the moment,.....

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a) Anna is reading a book.

read (v) đọc 

book (n) sách

b) Toby is flying a kite.

fly (v) thả

kite (n) con diều 

c) Peter is riding a bike.

ride (v) lái xe đạp 

bike (n) xe đạp 

d) Sue is behind the tree.

behind: đằng sau 

tree (n) cây 

e) No, he isn't. 

d) Yes, she is.

e) There is a ball.

How many + N số nhiều + are there? hỏi số lượng 

There is + a/an/one + N số ít  

f) No, he isn't.

g) There is a rabbit behind the tree.

How many + N số nhiều + are there? hỏi số lượng 

There is + a/an/one + N số ít  

`color{orange}{~MiaMB~}`

a) anna is reading a book

b)toby is flying a kite

c)peter is riding a bike

d)sue in the tree

e)no , he isn't

d)yes , she is

e)it's one ball

f)no , he isn't

g )it's one rabbit