Question 1

Why do we have both gekommen and sein at the end of the sentence?

Accepted Answer

This is the Perfekt Infinitive, which is used to make assumptions about the past. To express that something could have happened, you use the conjugated present tense modal verb (kann) along with the past participle of the main verb (gekommen) and its helper verb in the infinitive (sein). We use sein here instead of haben because kommen is a verb of motion.

Question 2

How certain is the speaker when using kann for an assumption like this?

Accepted Answer

When used subjectively, können expresses a simple possibility, roughly a 50 percent chance. It is similar to saying "could" or "might" in English. It shows much less certainty than muss (almost 100 percent certain) or dürfte (highly probable).

Question 3

If kann already expresses possibility, why does the sentence also use vermutlich (probably)?

Accepted Answer

It is very common in German to combine subjective modals with adverbs like vermutlich or vielleicht to fine-tune the exact tone. While kann alone is just a raw possibility, adding vermutlich makes it sound more like a working theory or an educated guess.

Question 4

Just as a quick refresher, why is it durch das Fenster rather than using the dative case for a physical location?

Accepted Answer

The preposition durch (through) belongs to a specific group of prepositions that strictly require the accusative case in all situations. Because of this rule, the neuter noun das Fenster remains das Fenster and does not change to the dative dem.

Der Einbrecher kann vermutlich durch das Fenster gekommen sein.

Breakdown of Der Einbrecher kann vermutlich durch das Fenster gekommen sein.

Questions & Answers about Der Einbrecher kann vermutlich durch das Fenster gekommen sein.

Learn Der Einbrecher kann vermutlich durch das Fenster gekommen sein and more in German