Here are some possibilities:
* "ac yn dda" (pronounced "ack un tha") - This is the most direct translation and is used when you want to say "and good" as a simple statement.
* "a da" (pronounced "ah tha") - This is a more informal way of saying "and good" and is often used in conversation.
* "yn dda hefyd" (pronounced "un tha hay-thoth") - This means "also good" and is used when you want to emphasize that something is good in addition to something else.
* "a braf" (pronounced "ah brahv") - This means "and nice" and is used when you want to emphasize the pleasantness of something.
The best way to choose the correct translation is to consider the context and the specific meaning you want to convey.