I.

$\text{1.}$ In the future, robots will be able to do many things like humans.

$\text{→}$ in the future chia TLD

$\text{→}$ be able to-V: có thể làm gì

$\text{→}$ many + N đếm dk số nhiều

$\text{2.}$ In the past, robots couldn't teach in a class but they can now.

$\text{→}$ In the past chia QKD

$\text{→}$ now chia HT

$\text{3.}$ Robots are able to guard our houses when we are away.

$\text{→}$ vế sau có we nên là our houses

$\text{→}$ we là số nhiều dùng are

$\text{4.}$ Some years ago, robots couldn't move easily but they are able to walk now.

$\text{→}$ year đếm dk mà trước nó có some nên thêm -s

$\text{→}$ ago chia QKD

$\text{→}$ sau V là adv

$\text{→}$ now chia thì HT

$\text{5.}$ Robots are able to do gardening but they aren't able to play sports and games like you.