In many parts of Spain, particularly small towns and rural areas, older people don’t speak English, only Spanish. However, most  young people learn English in school and are usually happy to practice so don’t be afraid to ask their help. In larger cities and even smaller towns that cater to tourists, it should be fairly easy to get by in English. That said, it is always useful to know some basic phrases in Spanish, and Spaniards will generally look favorably on attempts to speak their language.

 CORRECTION FROM ANOTHER MEMBER: In Madrid very few people speak English. Even in the museums the Spanish wasn't always translated.  So a mini-dictionary comes in very handy when visiting Madrid!

Useful Spanish phrases:

Buenos días   Good day, Good morning  
Buenas tardes  

Good afternoon, Good evening (generally used after lunch,
which is later than in the rest of Europe)  

Por favor   Please  
Gracias   Thank you  
Disculpe, Perdón  

Excuse "me", Pardon "me" (sorry for the quotations;
Trip Advisor flags personal pronouns in these posts)  

¿Cuánto cuesta?   How much does it cost?  
¿Dónde está ___?   Where is ___?
¿Habla inglés?    Do you speak English?  
¿Tiene usted un ___?    Do you have a ___?  
¿Podría ayudarme?    Could you help "me"?  
¡No comprendo!   "I" do not understand!  
 La Cuenta por favor  The Bill please
 ¿Cuánto te debo?

 How much do I owe you? (more informal than asking for the bill in a bar)

Pronunciation tips: j is pronounced like a hard "h" and not like English "j", so Jaén is pronounced (somewhat) like "ha-en". Also, Spanish vowels are never reduced to schwa like English vowels (If you're not sure what this means, think about how you pronounce the word "the" carefully -like "thee"- and then in everyday speech -like "thuh". The "uh" pronunciation is the schwa). Your Spanish will sound better if you always take care to pronounce the vowels faithfully. Also, remember that in some parts of Spain, z and c (when c is before e or i) are pronounced like English "th", so Cecilia is (approximately) "Theh-thee-lee-ah". However, s is not pronounced "th", and it's also not pronounced like "z" as one does sometimes in English so Susana is "Su-sah-nah".

Languages other than (Castilian) Spanish: Don’t forget that while Castilian Spanish (castellano or simply español) is official language all over the country, there are also various officially recognized regional languages in Spain: Galician (Gallego) in Galicia, Catalan/Valencian (Català/Valencià) in Catalonia, Balearic Islands and Valencia, and Basque (Euskera) in the Basque Country and Navarra. In Barcelona, for example, you may well be spoken to first in Catalan and then, if you don’t understand, in Spanish.