This is Already No Frivolous Post

[Note: Continuously updated with some suggestions from comments and a few edits]

I occasionally proofread texts written by non-native speakers. When I do, I make a note of the issues that come up the most frequently.

As a public service to my fabulous readers, and since we've been talking about Denglish lately, here's a list of some of the most common issues. (And yes, even highly-educated Germans who speak excellent English will still fall into these traps. English: So easy to master the basics, so tough get exactly right...)

• Avoid "deviant/deviating." Some dictionaries give "deviating/deviant" as a translation for abweichend, but deviant/deviating are rarely used in English. Plus, "deviant" has a strongly negative connotation; i.e. “he is a sexual deviant” or “his deviant opinions got him banned from the website”. Use “different,” “differing,” “contrary” instead
• Don't forget that you'll frequently need to negate with 'is'.  This is true especially when you're negating something specific, and always when you attach an adjective to the noun you're negating: "Lack of time is no sufficient excuse" becomes "Lack of time is not a sufficient excuse." "He is no good driver" is "He is not a good driver."
• Argumentation is barely an English word, and 'argumentations' certainly not.  It's all 'an argument' or 'her arguments.'
• Watch out for relative clauses. They are a real bitch for non-native speakers. Unlike in German, the comma is optional, and its presence or absence counts.

"The cars, which were parked outside the building, were damaged by the hail." [all the cars were parked outside/all were damaged]

"The cars which were parked outside the building were damaged by the hail." [some were parked outside, others not/those that were parked outside were damaged]

Misplaced commas can have serious consequences.  There have been lawsuits about them.  The following example shows why this might be:

"Crushed limbs, which present a threat to the vascular system, should be immediately amputated." [all present a threat/all should be amputated]

"Crushed limbs which present a threat to the vascular system should be immediately amputated." [some present a threat, some don't/the ones that do should be amputated]

• Watch out for so-called 'tonal particles' like schon, doch, ja, beziehungsweise or bzw., etc.  These words can usually be left untranslated, or their meaning can be conveyed by sentence structure. Don't just automatically translate schon as "already."
• Also, einerseits and andererseits usually don't need to be translated, the same goes for zunächst and sowie.
• Shorten your sentences. English doesn't work like German, it doesn't have as many built-in signposts (verb conjugation, adjective and noun declination, three genders) to let readers know how the moving parts of sentences hang together. Any sentence over 20 words is likely to be difficult to read in English, so break it up without changing the meaning.  And no matter what you're doing, omit needless words.
• Don't forget that the rules for constructing numbers change from language to language.  In American English, thousands are separated by a comma: "100,000.00" I learned this the hard way when I once tried to transfer "100.00" Euros from my European bank account to my American one. Since I naturally don't have one hundred thousand Euros to play around with (I'm a poor scholar, remember), amusing hi-jinks ensued.
• Adverbs always take an -ly.
• No "Firstly" or "Secondly", just "first" or "second."
• If you're going to use the word insofar, which, regrettably, sometimes cannot be avoided, it must always be followed by "as" plus a qualifying phrase, e.g. “insofar as profits remain” or “insofar as the item is subject to tax”
• The English word for kontrollieren is check or monitor, not control. Aktuell is currently or presently, not 'actual' or 'actually.' Eventuell is 'possibly' or 'maybe', not 'eventually.'
• Bis doesn't have a universal, one-size-fits all equivalent in English. When you're talking about a deadline for future work, bis becomes "by" -- "I need this document by (not until) Friday." In all other contexts -- that is, when you are not assigning a deadline, or talking about assigning a deadline, bis is translated as until: "I will work on the report until I feel it's ready for publication."
• The word "discriminate" is tricky. In English, unlike in German, it does not usually take a direct object ("You discriminated me!“). Instead, it always requires a prepositional phrase to make ts meaning clear. "Discriminate/Discrimination against" someone is evil and invidious and bad. "Discriminating between [two things] or among [several things], however, is not." 

Examples:   The law discriminated against immigrants. [bad, wrong, unfair, illegal]   

but, 

The human eye can discriminate [among] 4000 different separate colors. [among = many things, but you could also just say “discriminate [=tell apart] 4000 colors” just like in German, but without any pejorative connotation]   or

To understand Western art, you must be able to discriminate between Mannerist and Baroque styles. [between = two things]

• Don't translate the two-verb German perfect indicative literally: "He had bought some milk." This construction is used in English only to indicate a very specific anterior time-sequence, that is, to describe something that happened in the past before something else happened in the past: "He had gone to the store to buy some milk, but he didn't find any."
• Don't say "he took his fate into the own hands." Doesn't exist in English. Eigene in English is always, always translated with the help of a specific personal pronoun. "He took his fate into his own hands" or "She drove her own car to the hospital."

Comments

[nat]

Coming rather late to this, but regarding "-ly":

"Firstly" and "secondly" are indeed perfectly okay - I initially thought this might be a dialect difference (British vs. American) but it seems that most Americans have no problem with them. Unless you meant as adjectives rather than adverbs??

Speaking of adverbs, there are unfortunately plenty of exceptions to the rule that adverbs take "-ly". It's not quite a hard and fast rule.

[Norbert]

Another nice one is "We hope to see as much of you as possible!" at the end of an invitation.

[imethisguy]

"Here are some informations for you".
Although 'Informationen' is plural, there is no English plural of 'information'.

[Fast Gonzo]

I would like to add that there is a slight difference between "Erbrecht" (=law of succession) und "Erbrechen" (=vomiting).

The "German American Law Journal" (www.recht.us) has found out that
Babelfish translates "Amerikanisches Erbrecht" into "American vomit".

You can have a lot of fun with this:

"Erbrecht der USA", "Vomit the USA".

"Amerikanisches und Deutsches Erbrecht: eine rechtsvergleichende Studie",
"American and German vomit: one legal settlement-ends study"

Ich habe fertig!

[Sebastian Koppehel]

No "Firstly" or "Secondly", just "first" or "second."

Doesn't sound right to me. There's nothing wrong with "firstly" and "secondly."

[Koch]

Sweet! There is a massive space on Germany's collective professional fridge waiting to have a copy of this post taped up.

[BlackBellow]

I am always happy about such advice. For me it's still often "trial and error", even after 1 1/2 decades of active learning... My favourite "trap" is negation - endless fights with all those "anys" and "neithers".

[Jon]

Can you post the English to German version for those of us struggling with the German language? As a footnote, my German text refers to words such as aktuelle/actual as "false friends". Somehow this appeals to me.

[alala]

Don't forget the "since" pitfall:

"I've been in Germany since six years."

Argh.

[Alex]

Andrew:
"English: So easy to master the basics, so tough get exactly right..."
So true ... I curse the phrasal verbs!

Anon:
Oh yes, that's a nice one. Reminds me of a colleague whose answering machine always told me that he's actually not at his desk :-). Another one: eventually is not eventuell.

[anon]

If I may add something to the list: aktuell is NOT actual.
Actual is better translated as eigentlich.
Aktuelle is best as current.

just my $0.02