Questions & Answers about Ovaj telefon je noviji nego onaj.
Because telefon is a masculine singular noun, so the demonstratives have to match it.
- ovaj = this, masculine singular
- onaj = that, masculine singular
If the noun were feminine or neuter, the form would change:
- ova knjiga = this book
- ovo selo = this village
In your sentence, onaj stands for onaj telefon, so it is also masculine singular.
Noviji is the comparative form of nov.
- nov = new
- noviji = newer
So the sentence is using an adjective comparison: one phone is newer than the other.
Also, noviji is in the masculine singular nominative form, because it agrees with telefon.