Not all language errors sound the same to native ears. For example, while you may be frustrated with the chronic difficulty of distinguishing between pretérito and imperfecto, this is not a mistake that sounds particularly bad to a native speaker. However, you should pay attention to the following ten errors I have selected and, ¡por favor!, try to avoid them.
1. LA problema: The fact that problema, tema, sistema, teorema etc. end with an -a doesn’t make them feminine. They (all of them coming from Greek) are masculine: EL problema, el tema, el sistema, el teorema.
2. ME LLAMO ES Peter (my name is Peter): I love/hate this one. It is the epitome of the intrusiveness of the verb to be: He shows up even when he’s not needed. ME LLAMO Peter is the correct translation.
3. En la foto ES un hombre y una mujer (In the picture there’s a man and a woman): Same pattern. En la foto HAY un hombre y una mujer.
3. EXPENSIVO: This is a creation of my students at Fordham University. Someone said it once and now it has spread, causing serious damage. Please! Expensive in Spanish is CARO.
4. ELLOS gustan: Gustar (to like) will have its own post in the future, but here you have two samples. You need to be aware that your brain will do whatever it can to avoid using le or les, choosing the more popular subject pronoun ellos. Correct form: LES gustan (they like, lit., to them they are pleasing).
5 SE gusta: Here se (which replaces le/les when two pronouns are together: Se lo dio la maestra. Te teacher gave it to him)- is used incorrectly alone. Correct form: LE gusta (he/she likes, lit. to him/her he/she/it is pleasing ).
6 Mi hermano ES veinte años (My brother is twenty years old): A classic. Again to be imposes itself: Mi hermano TIENE veinte años.
7 ¿Cómo estás? SOY BUENO (How are you doing? I’m good): This time we have two problems: Ser against its rival estar, and bueno versus bien. Correct reply ESTOY BIEN.
8 ¿Cómo estás? MÁS O MENOS. In Spain we never answer this way. More natural options: NO MUYBIEN (Not very well) or REGULAR (so so).
9. ES CALIENTE (It´s hot): Conversations about the weather suffer huge neglect: HACE CALOR.
10. AMÉRICA: For Spaniards, America is the whole continent. Use ESTADOS UNIDOS, instead.
Habrá más. More to come.