Using three verbs in a sentence

Question

I want to say

We should teach children to use mobile phones effectively.

There are three verbs in this sentence, sollen, unterrichten and benutzen. Because of this I am not sure of the word order. I've got wir sollen Kinder unterrichten and Handys wirksam zu benutzen. But I am uncertain how to connect them. So far I have got just them together

Wir sollen Kinder unterrichten, Handys wirksam zu benutzen.

However I feel like this is wrong. I was also considering that it could be something like

Wir sollen Kinder unterrichten, um Handys wirksam zu benutzen.

But surely this means 'We should teach children in order to effectively use mobile phones.' There is also the option of writing

Wir sollen Kinder Handys wirksam zu benutzen unterrichten.

But I think that option is totally wrong.

How would I use three verbs in a sentence like this?

Answer 1

Wir sollten Kinder unterrichten, Handys effektiv zu (be)nutzen.

This translation conveys the exact meaning of the English sentence. The German adjective/adverb wirksam doesn't match the verb (be)nutzen well. Stay with effektiv or use richtig.

A typical German way to express what you mean is turning a verb into a noun:

Wir sollten Kinder in der richtigen Nutzung von Handys unterrichten/schulen.

The verb beibringen allows to replace the prepositional object by an accusative object and the person who is taught as a dative object, which sounds a bit better to my ears.

Wir sollten Kindern die richtige Nutzung von Handys beibringen.

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Wir sollten Kinder unterrichten, um Handys effektiv zu (be)nutzen.

indeed translates into English

We should teach children in order to use mobile phones effectively.

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Wir sollen Kinder Handys wirksam zu benutzen unterrichten.

Yes, that sentence is doomed.

Answer 2

To get this out of the way first: It should be sollten (Konjunktiv II). And wirksam does not really work. I am not quite sure what effectively is supposed to mean here, so I am going to stick to effektiv as the other answer does.

Now to unterrichten. This is a slightly strange verb, as it can take an accusative object to either indicate who is taught

Ich unterrichte Schulkinder.

or what is taught

Ich unterrichte Mathematik.

You cannot have both as an accusative object, though. (Now that I think of it, this is similar in English.) If you want both then it is jemanden in etwas (dative) unterrichten.

Ich unterrichte Schulkinder in Mathematik.

Therefore, your first sentence would have to be

Wir sollten Schulkinder darin unterrichten, Handys effektiv zu benutzen.

Note that this sounds stilted, and that it describes more an ongoing process of teaching and not so much that something has been learned finally afterwards.

Let me mention the alternative of using a noun:

Wir sollten Schulkinder im effektiven Gebrauch von Handys unterrichten.

So let us look at other verbs. There is lehren. Now this is a really strange one, because it can take two accusative objects, jemanden etwas (accusative) lehren. Therefore, you can now use the construction that you wanted

Wir sollten Schulkinder lehren, Handys effektiv zu benutzen.

I do not really recommend this, because this use of lehren is somewhat dated. So let us move on to jemandem etwas (accusative) beibringen. This has an accusative and a dative object, so it is less exceptional.

Wir sollten Schulkindern beibringen, Handys effektiv zu benutzen.

This sounds most natural.

To your other variants:

Wir sollten Kinder unterrichten, um Handys effektiv zu benutzen.

This is grammatically correct, but it seems to say that teaching children will enable us to use phones better. Not what you want.

And as to word order in the correct sentences:

Wir sollten Kinder Handys effektiv zu benutzen beibringen.

I cannot think of a reason why this would be incorrect, but it does not read well, do not use it. Again, using nouns is an option.

Wir sollten Kinder den effektiven Umgang mit Handys beibringen.

Answer 3

It is correct to say it. Don't worry so much about it. Although the context changes if you wanted to structure it another way the meaning will be slightly different but it would still be correct.