The formula you want to use is

where:

P = principal amount (initial investment),

r = annual interest rate (as a decimal),

n = number of times the interest is compounded per year (monthly = 12, quarterly = 4, etc.),

t = number of years, and

A = amount after time t

So, in your question...

P = 2000

r = 0.06

n = 12

t = 2

01