Essere necessario, servire: occorre grande concentrazione in questo lavoro ai bambini occorrono molte cure anche impers.: non occorre che tu mi accompagni.
To be necessary, to serve: great concentration is needed in this work, children need a lot of care, even impers.: you do not need to accompany me.
Capitare, accadere, succedere: non vorrei che gli occorresse qualche guaio.
To happen, to happen, to happen: I would not want him to need some trouble.
Comparire, ricorrere: in quel testo la parola “amore” occorre 10 volte.
Appear, recur: in that text the word "love" is needed 10 times.