Questions about Spanish Adverbs:
Q: Why is it Ese carro es extremamente lento and NOT Ese carro es extremomente lento?
Adverbs formed with the suffix –mente are always formed using the feminine form of the adjective, regardless of if the adjective and corresponding noun are masculine. Adverbs DO NOT have number and gender agreement.
Q: Why is it Realmente no quiero ir allí and NOT Actualmente no quiero ir allí to say "Actually I don't want to go there"?
The adverb actualmente is a false friend that means "currently" or "presently". To say "actually" use realmente or en realidad.