86. It isn't necessary for you to finish the work today.

=> You don't have to finish the work today.

It isn't necessary for sb to V

= S+ dont have to V

87. Most people find it easy to eat with chopsticks.

=> Most people have no difficulty in eating with chopsticks.

have no difficulty in+ Ving

88. Ms Tham enjoys learning English.

Ms Tham is interested in  learning English.

S+enjoys+ Ving= S+ to be+ interested in + VIng

89. We plan to visit my grandparents next Monday.

=> We are going to visit my grandparents next Monday.

S+ plan to V= S+ tobe +going to+ V

90. Peter keeps forgetting his homework.

Peter  is always forgetting his homework.

S+ keep+ VIng= S+ tobe+ always+ Ving