What I found pretty confusing in my stats class is that we'd often just say

alternative hypothesis H1: variable IS NOT 0

or

alternative hypothesis H1: value of the variable is higher/lower than 0

but we would use the same t-values and all..seemingly?

or are the t-values for a one-sided distribution different than those from a 2-sided distribution?

If I do a one-sided hypothesis test do I just take the t-value of 2,5% instead of that for 5% b/c Im only looking at one side of the distribution?

hope this wasnt tooo confusing ?