# data[].attributes.body
1) We use can in order to express abilities that we have at the present times of speaking.

2) It can also express possibilities or help us to speculate on a certain observed pattern/tendency.

# data[].attributes.body
1) We use can't in order to express those things or abilities that we aren't able to do at the present times.

2) It can also express certainty based on observed evidences or tendencies.

# data[].attributes.body
1) We use could in order to express abilities that we had in the past but that may not be applicable any longer.

2) We also use it to express possibilities or to speculate in a more formal way on an observed pattern/tendency.

# data[].attributes.body
1) We use "couldn't" in order to express those abilities or things that we weren't able to do in the past.

2) It can also express certainty based on observed evidences or tendencies in a really formal way.