Learn Romanian: Vaca mănâncă mult.

In Romanian, the word for 'the' attaches to the end of the noun instead of being a separate word before it. The basic dictionary word for 'cow' is vacă. Because it is a feminine noun ending in -ă, you replace that -ă with -a to get vaca (the cow).

The dictionary says 'to eat' is a mânca. Why is it spelled mănâncă here?

Romanian verbs often change their inner vowels when they match up with different subjects (like I, you, or it). For the 'he/she/it' form of a mânca, the vowels shift around to become mănâncă. This is a very common verb, so it is best to simply memorize this specific spelling!

Could this sentence also mean 'The cow is eating a lot'?

Yes, exactly! Romanian only has one present tense. The word mănâncă covers both 'eats' (a general habit) and 'is eating' (an action happening right now). You can usually tell which meaning is intended based on the context of the conversation.

I have seen mult change its ending in other sentences. Why didn't it change to match the feminine cow here?

When mult describes a noun (like saying 'many cows'), it changes its ending to match that noun. But in this sentence, it describes the verb—it tells us how much the action of eating is happening. When used this way to mean 'a lot', it acts as an adverb and always stays in its basic, unchanging form, mult.