Aromanian is an Eastern Romance language with roughly 250,000 speakers, largely in Greece and North Macedonia. It is closely related to Romanian, with the major difference being in vocabulary: while Romanian has absorbed a great many words from the Slavic languages, Aromanian has instead been influenced by Greek.
Grammatically, Aromanian is similar to Romanian in many ways: both languages have three grammatical genders (masculine, feminine, neuter), both decline nouns, both append definite articles to the ends of nouns (a feature of the Balkan sprachbund), etc.. However, a difference is that while Romanian has verb infinitives, Aromanian lacks them entirely; as such, Aromanian forms the future and conditional tenses differently (these using an auxiliary verb and the infinitive in Romanian). Aromanian also forms the pluperfect with an auxiliary verb, whereas Romanian forms it synthetically (i.e. with a conjugation).