In Defense of "Does it need saying?" An in-depth look at the Doctor's refusal to say "I love you" to Rose Tyler.really great article! Thanks for breaking my heart all over again <==This article is great. Full of feels, but great.
The TARDIS translates it into English. They speak the Queen's English so the TARDIS translates it to the Queens English for them. They understand American English, therefore the TARDIS has no reason to translate.