Romance Languages:
* Portuguese: This is arguably the closest to Spanish, sharing a common ancestor (Vulgar Latin) and exhibiting similar grammatical structures, vocabulary, and pronunciation. They're mutually intelligible to some degree, especially in written form.
* Catalan: Spoken primarily in Catalonia (Spain), this language is also very close to Spanish in its grammar, vocabulary, and overall sound.
* Italian: Although slightly more distant, Italian shares many similarities with Spanish in terms of grammar, pronunciation, and vocabulary.
* French: Despite its pronunciation differences, French still has a lot in common with Spanish in grammar and vocabulary, thanks to their shared Latin roots.
Other Languages:
* Galician: This language, spoken in northwestern Spain, is considered a dialect of Portuguese by some linguists, and shares many features with both Spanish and Portuguese.
* Romanian: While further removed than the other Romance languages, Romanian still has notable similarities with Spanish, particularly in vocabulary.
Important Note: The degree of similarity between languages is complex and depends on various factors, including:
* Mutual intelligibility: How well speakers of one language can understand another language without prior learning.
* Grammar: The structure and rules of the language.
* Vocabulary: The words and phrases used in each language.
* Pronunciation: How words are spoken and the sounds used.
Ultimately, the "most like" is subjective and depends on what aspects of a language you're focusing on.