In British English we can differentiate between a verb and noun with spelling patterns. A common one is the ‘ce’ or ‘se’ ending.
noun verb US English
licence license license
practice practise practice
advice advise
device devise
The latter two are easy to remember because the pronunciation is different, but the first two sound the same.
In US (American) English there is no difference in spelling between verb and noun, but the words do not follow the same pattern (see above).
Some words that do not have a change in spelling.
There are many words that look like they belong to the same word family ('ice' or 'ise endings), but in fact do not have a spelling change. They use the same spelling whether they are verbs or nouns.
e.g.
‘ice’ ending ‘ise’ ending
slice promise
spice exercise
sacrifice disguise
invoice surprise