The Awful German Language (1880)

First of all, it is not German, but Old English, which is not particularly more similar to German than it is to any other Germanic language e.g. Icelandic.

Second, the idea that middle/modern English began as a pidgin is a very fringe view in linguistics; the vast majority of people who have studied the question would instead say that it indeed has a huge amount of French (or more precisely, Norman) influence, but not to the extent that we can say it went through a pidgin/creolization process.

IIRC (not sure about this) English is thought to have lost its case system mainly due to influence from Old Norse (which had a similar case system but with different and not mutually intelligible endings), not French.

While English is changing relatively quickly, German isn't. Children today read original texts from the Gutenberg era in school without any trouble.

Where I grew up, we actually read some old english texts in school. It was hard, but certainly doable, using just our knowledge of modern German and English and the local dialects (north frisian and low german).

How old? “Old English” is a term of art meaning the language exemplified e.g. by Beowulf or the writings of Aelfric, which I would be very impressed if you could read without special study, so perhaps you meant Middle English or Early Modern English.

As an example, the beginning of Beowulf reads: “Hwæt! We Gardena in geardagum, þeodcyninga, þrym gefrunon, hu ða æþelingas ellen fremedon.”

Middle English is the language of Chaucer and Early Modern English that of Shakespeare.

As a native English speaker (who can also read German at an intermediate level), I can read Shakespeare with some difficulty (relying on the copious footnotes that modern editions are peppered with), Chaucer with extreme difficulty, and Beowulf not at all.

Well that's a good question I don't know the exact answer to. So I looked at the examples you provided.

Early Modern English:

Shakespeare's early modern English is something I can read fluently (and I know we read & acted his plays in original in school). To me that's basically the same as current English, just with slightly different vocabulary.

Middle English:

Original: "Whan that Aprill, with his shoures soote" / Platt: "Wenn dat April, mit sien schuren sööte" / English: "When that April, with his showers sweet"

Original: "Inspired hath in every holt and heeth" / Platt: "Inspireert hett in elk Holt un Heid" / "Inspired has in every wood and heath"

That's probably the one we read in school. If you read it, it sounds like a grandparent combining mispronounced english and their dialect.

Old English:

Original: Cnut cyning gret his arcebiscopas and his leod-biscopas and Þurcyl eorl and ealle his eorlas and ealne his þeodscype, tƿelfhynde and tƿyhynde, gehadode and læƿede, on Englalande freondlice

Platt: Knut König greet sien Arzbischopes un sien Lüüd-Bischopes un Thorkell, jarl, un all sien jarls un all sin löödschaft, twalfhunnerte un tweehunnerte, widmete un laien, Engellande fründliche

English: Cnut, king, greets his archbishops and his people-bishops and Thorkell, earl, and all his earls and all his people ship, twelve hundred and two hundred, ordained and lay, in England friendly.

Now this one is much harder, especially as the spelling is getting even weirder, and the vocabulary includes a lot more danish words than middle English would, but pretty much every word exists in either modern English, or modern Low German.

> As a native English speaker (who can also read German at an intermediate level), I can read Shakespeare with some difficulty (relying on the copious footnotes that modern editions are peppered with), Chaucer with extreme difficulty, and Beowulf not at all.

The German dialects are clearly divided between Low German and High German, with different vocabulary, grammar, and pronunciation. Standard German is based on the vocabulary and grammar of High German, so it won't be very helpful.

The closest living relative to Old and Middle English would be North Frisian, but Low German as spoken in Anglia today is still relatively close (as shown above).