Is the ordinal number "zuerst" only acceptable in colloquial speech and writing?

Question

While practicing writing this sentence fragment (“First you must select a good cookbook, then ...”) in German using each of my two ‘silent tutors’(translate.yandex.ru and translate.google.com) to check the correct way to say or write that fragment I found that the translations returned by my two tutors was functionally the same, but that they had differences in word order and familiarity with the person to whom my sentence fragment might have been directed.

Here is what my two tutors had replied:

(Yandex): Zeurst müssen Sie wählen Sie ein gutes Kochbuch, dann ...

(Google): Zeurst musst du ein gutes Kochbuch auswählen und dann ...

In checking my German, my Russian tutor (Yandex) returned my sentence in ‘polite’ word usage, while my American tutor (Google) used ‘familiar’ word usage. However, you’ll notice that both of my tutors went on to consistently correct my use of the word “Erst” (an adjective) to “Zuerst” (an adverb) whenever I made small revisions to either the English or the German sentences.

(A grammar anomaly indirectly related to my question is in the American version (Google) where “und” is required before the word “dann” -- why, I don’t understand.

My question is this: Since in the ‘Ordinal Numbers’ section in many of my German grammar books (including Duden’s “Die Grammatik”) the word “zuerst” is not mentioned nor defined; the only German grammar book that did mention it was only in the “Wörterverzeichnis” section of my English language grammar book Colloquial German (by P. F. Doring, 1975 edition or later).

So, is the word “zuerst” okay to be used, but okay only in colloquial [i.e., everyday] German speech and writing, and is the “zu” in that word a separable prefix?

Answer 1

The meaning of zuerst slightly differs from erst in that, by the prefix "zu-", additional information is given. It thus has a more absolute meaning than a simple erst (cf. English first and at first). I'll give an example at the end of this answer.

Hence, neither is zuerst limited to colloquial speech, nor is "zu-" separable under any circumstances.

However, there is a bit of an overlap in usage, as you pointed out in the example, where the use of "zu-" is really optional:

Zuerst musst du ein gutes Kochbuch auswählen und dann ...

Here you might as well write:

Erst musst du ein gutes Kochbuch auswählen und dann ...

Example

To make it a bit more clear, consider the following example:

Wenn er nach Hause kommt, schaltet er zuerst den Fernseher an.

In this sentence, it is clearly stated that the very first thing he does after coming home is to turn on the TV.

Answer 2

First of all (or zuerst): you'll never find zuerst in a list of Ordinal Numbers, because it is not a number.

The foremost usage of zuerst is to sequentielly order things to be done - which is exactly what you wanted to translate. So zuerst is completely correct in both translations (others things are not, but more to that further down).

Zuerst is also used if you want to express an order in time (which also refers to your example, but to a lesser extent), like e.g. "zuerst eroberten die Römer die Kleinstaaten auf der italienischen Halbinsel, danach dann die übrigen Völker Europas" (I don't know if that is historically correct, btw).

And finally zuerst may also be used with the meaning of erst.

So, to summarize it, and also answer your questions: Using zuerst in this context is completely OK and is not in any way just colloquial speech. The zu in zuerst is - to my knowledge - not a prefix of erst; rather zuerst is a word of its own.

Now to the other mistakes both your tutors have made: Your first tutor (Yandex) seems to have problems with the order of phrases in german. The sentence "Zuerst müssen Sie wählen ein gutes Kochbuch, ..." (I assume the double word Sie in your example was a typo from your side - otherwise this would be a different error) is completely wrong. Google does a much better job here. On the other hand did Yandex choose the correct form of familiarity. As this sentence seems to be addressed to an unknown audience you would never use Du, but always use Sie.

Finally - the use of und (or here und dann) as in the Google translation or the use of a two comma separated independent clauses as in the Yandex translation is interchangeable.

Answer 3

I have no idea which Duden you searched, but "zuerst" is a perfect german adverb and in no way colloquial at all.

But your example shows quite nicely: online translaters are crap... The yandex translation is simply wrong. If you use the more formal way to say something, then it would be:

Zuerst müssen Sie ein gutes Kochbuch auswählen, dann...

It is possible and correct to use the verb "wählen" hier, but a german speaker would rather not use it and stick with "auswählen" in that sentence.

If you address the reader with "Du" or "Sie" depends on context and your chosen style.

Regarding comma or und: that is absolutely up to you and depends on your preference. Both mean exactly the same, it is just a matter of style and surrounding text, if the sentence sounds better with or without the "und".