Q Why would Scotland keep the pound if it votes for independence from the UK?
A The Scottish government knows that losing sterling would have a detrimental impact on its economy by hampering exports to the rest of the UK.
They use the lever that such a change would also damage trade for businesses in the rest of the UK which deal with Scotland.
The Westminster government believes Scotland would need its own currency under independence.
It points out that if it continued to use sterling, the Bank of England would be making decisions on interest rates etc without considering the needs of Scotland.
In essence, it says Scotland can't keep using sterling after a 'yes' vote.
Q Why is the Bank of England governor against Scotland using sterling?
A The same reason as the government. He pointed out yesterday that different countries using the same currency with different monetary policies was a recipe for disaster and used the Eurozone crisis as a still-hot example.
Q What currency could Scotland adopt under independence if it doesn't use sterling?
A Nobody's sure. It's likely that given independence, Scotland would vote to join the European Union but Alex Salmond is unlikely to want to use the euro.
More than likely it would probably have to form its own currency.
Q What have Mr Carney's comments done to the call for an independent Scotland?
AThe Eurozone comparison will have rocked voters. By pointing to a huge hole in Alex Salmond's plans, Mr Carney has hit confidence where it hurts: in the wallet.
Q What does an independent Scotland mean for Northern Ireland?
AAny number of things amid any number of permutations.
An independent Scotland has a trade deficit so it will have to cut spending or raise taxes – both factors which could damage export from here to the region.
Under independence, Alex Salmond (left) could also cut corporation tax if he chose, leaving Northern Ireland caught between it and the Republic with a business tax rate nearly half that of ours.
That would do very little to attract inward investment.