Questions & Answers about Ovaj muškarac je lončar.
Because ovaj has to agree with muškarac in gender, number, and case. Muškarac is masculine singular nominative, so the correct demonstrative is ovaj.
Compare:
- ovaj muškarac = this man
- ova žena = this woman
- ovo dijete = this child
Not exactly.
- muškarac specifically means an adult male / a man
- čovjek can mean human being, person, or sometimes man, depending on context
In this sentence, muškarac is the more precise word if you want to identify someone as male.