False friends are words that look similar but mean different things. For instance, "fabrici" sounds like "fabric" but means "factory" (fabrika). Krstarica flags these differences.
Serbian verbs have aspects that don't exist in English. The dictionary helps by showing translations like "pisati" (to write, imperfective) vs. "napisati" (to write, perfective/completed action). srpsko engleski recnik krstarica
Here are some helpful resources: