Is, are, was, were, see the Related Link below for more.
"Seem" has a present indicative tense, generally considered the first principal part of a verb.
Because "don't" is a contraction you have to spell out the original words in order to see which part is the verb. "Do not" is the original phrase. "Do" is the verb because is represents the action.
-ate
arrange
Hydroelectric, hydroelectricity, hydrogen, etc...