Learn Hardcore German: Ich schaue in das Buch und lese langsam.

In German, using in das Buch (often contracted to ins Buch) indicates looking into the contents of the book. By contrast, auf das Buch would mean you are looking at the cover (on top of the book surface). So in das Buch is correct here when you want to convey looking inside and reading.

What is the function of the word und in this sentence?

Und simply connects two actions you’re performing: the action of looking into the book (Ich schaue in das Buch) and the action of reading slowly (und lese langsam). It works exactly like "and" in English, joining two verbs or phrases.

Why does the article das remain the same here instead of becoming den?

The preposition in can be followed by either the accusative or the dative case, depending on the meaning. When it implies movement into something, it requires the accusative, so das Buch stays in its accusative form (which looks the same as its nominative form for neuter nouns). You see das Buch in both nominative and accusative. If it were masculine, like der Tisch, it would change to den Tisch in the accusative.

Why is langsam at the end of the sentence?

In German word order, adverbs typically come after the verb or near the end of the sentence. Placing langsam at the end adds emphasis to how you are reading. You could also say Ich lese langsam separately, but in longer sentences, the adverb commonly appears toward the end.

Is there a difference between ich schaue and ich sehe in such a context?

Ich schaue (I look) places emphasis on the act of directing your eyes or attention towards something, whereas ich sehe (I see) generally means perceiving something with your eyes. Using ich schaue in das Buch suggests an intentional action—actively looking. Ich sehe das Buch is more about noticing or perceiving it visually.

Why do you use the simple present tense in German here?

In German, the simple present tense (Ich schaue, ich lese) can describe both current ongoing actions and repeated actions or habits. In English, you might say "I'm looking into the book and reading slowly," but in German you typically use the present tense for both. That’s why Ich schaue and ich lese suffice to express the ongoing action.