That's what makes English a Germanic language: it's descended from Proto-Germanic via a continuous chain of child acquisition. English doesn't have that relationship with any Romance language.
It does not? Not even in way longer timeframes?
Sorry, to clarify: English isn't
descended from any Romance language, any more than the Romance languages are descended from English. It does have a
common ancestor with the Romance languages, however: Proto–Indo-European, probably spoken some 7000 years ago in the vicinity of the Black Sea.
I always thought all modern languages using latin letters would have one common ancestor.
Hang on there: as noted above,
writing systems are totally unrelated to linguistic descent. English has a fairly close common ancestor (less than 2000 years ago) with Yiddish, which is written in the Hebrew alphabet. It shares the more distant Indo-European ancestor with, for example, Russian (Cyrillic alphabet) and Persian (Arabic alphabet)—of course, that ancestor existed millennia before the Latin, Cyrillic, or Arabic alphabets were invented.
Meanwhile, another modern language using the Latin alphabet is Vietnamese, which is related to Cambodian and a bunch of other Southeast Asian languages I've never heard of.
Even more, I always thought all modern languages would have some common ancestor, some ancient language with probably different properties that we assign to languages now (i.e., something we may not call language today, but a form of communication).
This is highly controversial, and from the standpoint of linguistic data there's no good evidence for or against it.