Best Answer - Chosen by the Asker
Your teacher is right:
"Ich mag Bücher lesen." is wrong, but:
"Ich mag es, Bücher zu lesen." is correct.
And in my eyes there is no difference between this sentence and:
"Ich lese (so) gern Bücher."
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When to use "mögen", when to use "gern"?
Well, you can use them equally in most cases, you do just have to use them grammatically correct:
- Ich lese gern Bücher = Ich mag es, Bücher zu lesen
- Ich mache gern Sport = Ich mag es, Sport zu machen
- Ich schwimme gern = Ich mag es, zu schwimmen
- Ich zeichne gern = Ich mag es, zu zeichnen
Generally it is better to use "gern" instead of "mögen".
Native speakers use "gern" mostly when they speak to each other.
Also if you write an essay it is more common to use "gern".
But it is grammatically NOT wrong to use "mögen", if you use it correctly.
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Finally, I must contradict gerigerald. "mögen" does not mean much more than like (gern).
It can be used equally in most cases.
And:
Ich mag dich. (I like you)
does exactly mean the same as:
Ich hab dich gern. (I like you)
In my eyes, the second sentence is even stronger.
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I hope I could help you and maybe you have to read the whole answer twice =)
Feel free to ask any additional question !
