How many teaspoons are 0.5 milliliter?

Answer 1

1 teaspoon is 5 ml, so you'll need one tenth of a teaspoon but this will be difficult to measure and also:

"In practice, they may hold anything between 2.5 mL and 6 mL of liquid, so caution must be employed when using a teaspoon to measure a prescribed dose of medicine."

So be careful.

Answer 2

There are approximately 0.1 teaspoons in 0.5 milliliters.