This is the 108th most frequent Czech word.
dobře
"Well" or "okay."
In this sentence, "dobře" is used as an adverb to describe the manner in which the action is performed.
Děláš to dobře.
You are doing it well.
Here, "dobře" is used in a fixed expression to indicate a positive state or outcome, functioning as part of the clause to signify 'it is good'.
Je dobře, že jsi tady.
It is good that you are here.
In this context, "dobře" again functions as an adverb, describing the ability or quality of the action, which in this case is speaking Czech.