"I have another question, but I'm not sure whether this is the right group to ask it. If it isn't ... = from Dutch 'Sinterklaas' , but I am not sure about the last one. Is there anyone who knows others?"
Dike/*** is related to OE "ditch" and evidently came with the Danes. I don't know how old the pronunciation is in terms such as "Offa's " or "Wansdyke" (in areas well away from Viking settlement) but I wonder if they suggest that it's even older. No doubt OED has more on the subject. "" is the standard term for a ditch or bank in my region (E. England). There's a village called which stands by the old Roman(?) "Car ". There are many Danish place name elements locally.
AFAIK, "Polder" isn't really naturalised into English as such. We only use it as the name of the reclaimed land in the Netherlands. We describe the equivalent as "fens" (or The Fens) in eastern England - whether drained or not. I believe there's a similar element (ven?) in some Dutch place names. There are also the Somerset Levels and Romney Marsh in other parts of the country - and perhaps other local names for marshy or reclaimed land.
The Holland area of Lincolnshire has a lot of fens and has had a lot of Dutch influence but the name is ancient and arose independently, meaning low-lying land.
Some say the word "***" came from Dutch seamen (careful how you say that) in the C16th but it doesn't seem to be confirmed.
Phil C.