If Queen Elizabeth II is on the front of the coin, it could be from any one of the 50 plus Commonwealth countries. If no country name is on the coin, it is probably British.
It depends on the denomination and condition of the coin. "Elizabeth II Regina" means "Elizabeth the Second, Queen", and "South Africa Suid-Afrika" is simply the name of the country, first in English and then in Afrikaans. All coins issued in South Africa in 1955 had both phrases ("Elizabeth II Regina" and "South Africa Suid-Afrika") on them.
Have another look at your coin. Elizabeth II was not born until 1926 and her coronation was in 1953.
It depends, please post a new question with the date of the coin, denomination and the country of origin.
It is an English Penny.
That depends on what country it was issued in, what denomination it is and what condition it is in.
what is a Canada 5 dollar coin of elizabeth 2 is worth
That motto appears on ALL coins of ALL countries in the British Commonwealth. Please post a new question with the coin's denomination and country of origin. If there's no country shown the coin is from England.
Nope
Any 50 cent coin with Elizabeth II on it will be worth 50 cents in whatever country it came from.
50 cents suckers
England
Not enough details. What country? (if there's no country on the coin, it's from the U.K) What date? Please post a new question.