Questions & Answers about Ovaj plan je definitivno bolji.
Ovaj means this, so ovaj plan means this plan.
You can say just plan if the context already makes it obvious which plan you mean, but ovaj points to a specific one more clearly.
Also, ovaj has to agree with the noun:
- ovaj plan = this plan (masculine singular)
- ova ideja = this idea (feminine singular)
- ovo rešenje = this solution (neuter singular)
Because plan is a masculine singular noun in Serbian.
The demonstrative this changes form depending on the gender of the noun:
- masculine: ovaj
- feminine: ova
- neuter: ovo
Since plan is masculine, the correct form is ovaj plan.
Je is the 3rd person singular form of the verb biti (to be), so here it means is.
So the structure is:
- Ovaj plan = this plan
- je = is