Learn Dutch: De verslaggever zag een schokkende gebeurtenis in het dorp. - The reporter saw a shocking event in the village.

Here, schokkende is an adjective describing the noun gebeurtenis. Since gebeurtenis is a de-word, the adjective gets an -e after een. If it were used as an adverb of degree modifying another adjective (like 'a shockingly big event'), it would not get the -e: een schokkend grote gebeurtenis.

How can I remember that gebeurtenis is a de-word?

Nouns ending in the suffix -nis (like de betekenis or de kennis) are almost always de-words. This gender is what forces the -e ending on the adjective schokkende in this sentence.

Is schokkende actually a verb form?

Yes, it is the present participle of the verb schokken (to shock). In Dutch, present participles are formed by adding -d to the infinitive. When used as adjectives, they follow the normal adjective inflection rules, which is why we add the extra -e here.

What are the component parts of verslaggever?

It is a compound of het verslag (the report) and de gever (the giver, from the verb geven). So a reporter is literally a 'report giver'.