1) I swear by my mom I didn't do that. :cross:
2) I swear on my mother's life I didn't do that.
3) I swear on my job I didn't do that. :cross:
Please check my sentences.
We don't use 1 or 3. If your mother is alive, you can swear on her life. If she's dead, you can swear on her grave.
If you have a question about the English language and would like to ask one of our many English teachers and language experts, please click the button below to let us know: