"This shirt costs $50."
"This shirt is costing $50."
Which is correct? Why?
The first sentence - "This shirt costs $50" - is correct because the price of the shirt is fixed; it's a fixed state and therefore we use a state verb, costs.
Costing can not be used for a fixed state because the ...ing means that something is happening now and it will change soon. It would therefore be correct to say "I am buying a shirt" because you are buying it now; soon the action the action will be finished. Likewise, we can not say "I buy a shirt" for a present, temporary, situation. State verbs are used to describe actions which don't change: "I owe you $5" - you either owe someone money or you don't. That's why we can't say "I am owing you $5".
Read through the examples below and choose the correct verb form:
If you want more information on state verbs, try this lesson!
