Translation of moisten in German

Arete means earring. Is it only in Mexico, regional? earring has multiple translations in Spanish, some are regionalism, others not. Arete, pendiente, caravana, and some others. But they are widely understood.
I will be creating an additional study with a student (his name is Juan), which may appear in local newspapers in the future (in English). However, this may take a couple of weeks too.
What is the past tense of 'to swim'? So either you say, I was swimming or yesterday I was swimming. Or: I was running yesterday vs. yesterday, I ran. You know the answer? I have no clue.