I was born and raised in US in a bi-lingual household (Greek & English).
In high school I studied German and, to my teacher’s amazement, I picked up both the German language and the accent quite easily.
I owe this to both my English AND Greek language fluency. The English connection is intuitive to make since it is a Germanic language. However, German doesn’t always come easy to native speakers of English. The reason being a lack of familiarity with declensions. German, like Greek and Latin, relies on declension (the variation of the form of a noun, pronoun, or adjective, by which its grammatical case, number, and gender are identified) whereas English does not.
Also I detected vestiges of Greek vocabulary ensconced within German vocabulary but non-existent in English.
1) The simplest pronoun in English is “I”. One letter. But it derives from the German “Ich” which has a more complex sound. I found it super easy to embrace this word due to its similarity to “Εγώ” (“I” in Greek and in Latin- “ego”).
2) The throaty “chh” (guttural) sound was a piece of cake (due to my Greek skills). Greek and German are both guttural languages. But English is not.
3) The pronoun “you” in English is very similar to “du” in German. But there are two forms of “you” in German: du (informal) and Sie (formal). So how is “Sie”related to “you”? It ain’t. But it is an obvious vestige of “εσύ” (eh-SEE), Greek for “you”.
4) The construction of sentences (word order) in English is extremely important. Not so in German or Greek. In the latter two languages you can jumble word order and still wind up with acceptable grammar.
Theses are just a few cases that I can recall (it’s been 37 years since I graduated HS). But if you poke around I’m sure you’d find more clues.
So, despite English being a Germanic language, I find German to be more closely related to Greek.