Learn Dutch: Die jonge manager schijnt erg zelfverzekerd en betrouwbaar te zijn. - That young manager is rumored to be very self-confident and reliable.

The verb schijnen is used for hearsay, meaning you heard this information from someone else (like a rumor). If the sentence used lijkt, it would mean the speaker is judging the manager based on their own direct observation.

Why is te zijn pushed all the way to the end of the sentence?

The verbs schijnen, lijken, and blijken are used together with a te + infinitive construction. In a main clause, the conjugated verb (schijnt) takes the second position, and the te + infinitive part (te zijn) gets kicked to the very end of the sentence.

Why does jonge get an -e added to it?

Manager is a de-word. Because it is specified by the demonstrative pronoun die (that), the adjective jong gets the standard -e ending added to it.

I thought erg meant 'bad' or 'terrible'. Why does it mean 'very' here?

While erg can mean 'bad' on its own, it acts as an intensifier meaning 'very' or 'really' when placed right in front of an adjective, much like the word heel. Here it intensifies zelfverzekerd (self-confident).