If you have dual nationality, you can stay for as long as you want to and can afford.
Indefinitely
In the UK, it will stay for about two months :)
How long a UK resident can stay abroad is up to the country the person is visiting. For example, a UK resident can stay in the United States 3 months without a visa, and longer with one. Some countries will only allow him to stay there two weeks, and many countries require the UK resident to obtain a visa before traveling. The visa will specify how long he may stay.
5years
11 years
No ! They can only stay as long as they are studying - then they have to return to their country of origin.
you can stay as longest you want for a dAY TWO OR THREE
They can be removed after 5 years.
If what you're asking is how long can a Polish immigrant stay for in the UK, the answer is: infinitely. Both the countries are in the EU and EU nationals can visit and stay in each other's countries without limits. If an EU immigrant, including Poles, were to live in the UK long enough (a few years), they might be eligible for the status of a Resident or - to apply for a British citizenship.
If you have a Malaysian passport, you can stay up to 6 months in the United Kingdom.
In the UK they will remain on your licence for four years.