Very similar, but not quite… There is always a difference of meaning between these pairs of nouns in Spanish, where the masculine word (usually ending in -o) and the feminine word (usually ending in -a) have a totally different meaning. If you take a look at this funny comic strip, you will find some help to understand the meanings of these confusing Spanish words.
This is what happens in suelo and suela, where suelo (masculine) means floor and suela (feminine) means sole. Or in coco (masculine) that means coconut, or coca which refers to the famous pop Coca-Cola or Coke.
If you want to know more, don’t hesitate to take a look at Munguía’s works, where the cartoonist has made a compilation of those pairs of confusing nouns or Parejas disparejas (as well as other word games) by drawing them in a very funny way. Remember that, in Spanish, most of the nouns ending in -o are masculine and most nouns ending in -a are feminine, but not always: there’s a huge list of exceptions: el problema, la mano, el mapa, el tema…
And, if you want to know more, don’t hesitate to try one of ELINQUA’s Spanish online lessons, that you will be able to take quickly and easily, without moving from your couch and just with an Internet connection and a Skype account.