* Fy nghartref: This is the most common and general way to say "my house." It literally translates to "my home."
* Fy nhŷ: This is a more literal translation of "my house."
* Cartref: This simply means "home" and can be used to refer to your house without explicitly saying "my."
* Y tŷ hwn: This means "this house" and can be used to refer to your house if you are pointing at it.
* Y tŷ yma: This is similar to "y tŷ hwn" but is slightly more formal.
The best way to say "my house" in Welsh depends on the situation. If you are speaking to a friend, you might use "fy nghartref." If you are writing a formal letter, you might use "fy nhŷ" or "y tŷ hwn."