Ability and capability
Both nouns are often used interchangeably. This is not wrong but there is a difference. Ability means that you are able, you are skilled and have the time and capacity right now to execute a task or follow up actions. Capability expresses that potentially you can execute the task, you have the ability but other circumstances are holding you back, whether it is time constraints or something else.
How to express
You will need a verb in English to express ability or capacity. This means you need an auxiliary verb followed by a base verb.
In this case, you use -can, could and will-.
I can arrange the meeting for next week. (Yes, I can)
I will arrange the meeting for next week (Yes, I can and I will do)
I can't arrange the meeting for next week as I am too busy. (No I can't, but you are capable)
I could (or can) arrange the meeting for next week but it is not my job. (Yes I can, but I won't, but you're capable)
You also can express ability or capability in a sentence using other verbs, e.g. - to be able to- or -to manage-. They can be used standalone or with a modal verb.
I am able to find another engineer to look at the problem. (Yes, I can)
I will manage to find another engineer to look at the problem (Yes, I can)
I manage the feedback myself. (Yes, I can)
Present, Past, Future
So for the present we use mostly can, could for the past and will for the future. But what about -could- in our example sentence. I could arrange the meeting for next week.
Could, in this case, is not the past, but expresses a more formal and polite way.
Therefore, could is also used frequently in questions. Grammatically, "Can you pass me the agenda, please?" is a correct sentence, but much better would be to say "Could you pass me the agenda, please?
Try it yourself
Please find below a link to the exercise and the document for downloading.
Subtle differences, but I am sure you can do it.