People need help, but sometimes the circumstances are such that you cannot do it, or the individual tries to hang his problems on you. If you refuse, in any case, you need to be polite and try not to offend the person.
In certain life situations, you need to be able to say "no". This greatly simplifies life and eliminates problems. Sometimes it is very difficult to refuse a person, however, consent can entail a number of difficulties. You do not need to be rude, especially if you have to communicate with this individual further. There are certain ways to politely decline.
Long-term consent
This is a situation in which a person does not seem to refuse, but at the same time does not fulfill the request. It stretches the execution of the task in time. The individual waits and waits, he gets tired of it, and he turns to another person for help. Of course, a person may be offended having lost so much time waiting, so it is better to use this method as little as possible.
Lack of time
You can make good arguments about the impossibility of doing something, referring to the total workload. As a courtesy, you can offer your services after a fairly long period of time.
Difficulties
In this case, you can tell the person about the difficulties in life that you are experiencing. Make it clear that now is not up to him.
These are the most common ways to politely decline. Each situation is individual and you can find a new psychological approach to this issue.