is a large current account surplus ever a negative situation for a country?

Sure, a large LONG-TERM current account surplus can cause problems.

But first, the definition of "current account" has different meanings to different economists. For my purposes, I assume a simple situation wher "current account" is simply "balance of trade"; a surplus means a country is exporting more than importing.

One must ask why there is an account surplus. It is likely because of some government intervention. In which case you have an economy based on Mercantilism. (An economic belief common in 17th and 18th century europe.) Google Mercantilism for the multitude of problems with a system demanding high-exports and low-imports

Use this as a start.

Lotsa luck

For me, or shall I say my book the CA= EX-IM, which you also wrote balance of trade.

I know that perfect economy is when the supply equals demand. But I can't see why a surplus for a country is bad!!
More money means that the country can save more and therefore invest more as it desire, plus it will lead to a strong currency...

But then again if one country has a large surplus another country must have a large deficit...

OK I will look read about Mercantilism:)

Suppose that you had $100. ABC bank is offering 5 percent simple interest. DEF Bank is offering 10 percent simple interest. Which bank would you deposit your money into if you wanted to earn more interest?

Yes, a large current account surplus can sometimes be a negative situation for a country. A current account surplus is formed when a country's exports exceed its imports, leading to an inflow of foreign currency. While having a surplus can be beneficial in some cases, there are several reasons why it might be negative:

1. Exchange rate appreciation: A large surplus can lead to an appreciation (increase) in the country's currency value. This makes exports more expensive and imports cheaper, which can harm the competitiveness of the country's industries, potentially leading to job losses.

2. Dependence on external demand: A significant surplus often indicates that a country is heavily reliant on external demand for its goods and services. This can make the economy vulnerable to changes in global market conditions, such as a decrease in demand from key trading partners, which can negatively impact economic growth.

3. Misallocation of resources: A persistent current account surplus might signal that a country is overly focused on exporting and neglecting other sectors of the economy. This could lead to a misallocation of resources, limiting diversification and inhibiting long-term economic development.

4. Capital outflows: A current account surplus represents a net capital outflow, as the surplus must be invested in foreign assets. This can result in an accumulation of foreign reserves or investments abroad. While diversifying investments can minimize risk, excessive capital outflows might limit domestic investment opportunities, hindering economic growth and development.

To determine whether a large current account surplus is negative or not, it is crucial to consider various economic factors, such as a country's specific circumstances, the sustainability of the surplus, and its long-term implications for economic stability and growth.