a) I am watching
b) He is doing
c) We are looking
d) You are sitting
e) He is going
f) She is playing
g) We are swimming
h) He is saying
Explanation: These sentences require the present continuous tense. The structure is: subject + am/is/are + verb-ing. 'Am' is used with 'I', 'is' is used with singular subjects (He, She, It), and 'are' is used with plural subjects (We, You, They).