This paper provides an overview of the runs submitted to TRECVID 2018 by ITI-CERTH. ITI-CERTH participated in the Ad-hoc Video Search (AVS), Instance Search (INS) and Activities in Extended Video (ActEV) tasks. CERTH's AVS task participation is based on a method that combines the linguistic analysis of the query with concept-based and semantic-embedding representations of video fragments. The INS task is performed by employing VERGE, which is an interactive retrieval application that integrates retrieval functionalities that consider mainly visual information. For the ActEV task, CERTH deploy a novel activity detection algorithm that is based on human detection in video frames, goal descriptors, dense trajectories, Fisher vectors and a discriminative action segmentation scheme.