I understand it, or That I understand. Depends on the context it is use in
"No entiendo, porque..." means: I don't understand because "No entiendo, ¿por que?" means: I don't understand, why? (the meaning depending on if por que was one or two words) (to add one more meaning To Laila's answer) "No entiendo por que!" made as a statement can mean " I do not understand why! " (disbelief)
"I understand, I just can't explain it." --> "Yo comprendo, puedo no explicar."
"I understand how you would say it"
No comprendo lo que usted decir No entiendo lo que dices
entiendo lo que dices
Look! What I...
Literally it means: "What I don't understand every time is what the h... you are talking about/saying"
Spanish sea lo que sea means "come what may".
This is what I do.
No entiendo lo que dices. Estoy confundida.
No creo que entiendo lo que Ud. quiere decir.
" to do what I have is God"