You probably don't have to think too hard to figure out what the Spanish abbreviations a.m. and p.m. mean. But how about d.C. and ONU, which are also very common? To find out, check out our list of the most common abbreviations you're likely to run across.

Most clauses that begin with si (the equivalent of "if") are what is known as conditional clauses. Which verb you use as part of that clause depends a great deal on how likely you believe the condition to be true. Thus a clause such as si yo fuera tú ("if I were you") uses an imperfect subjunctive verb because it's not likely to be true. (In this example, note that the English also uses the subjunctive.) This concept is further explained in our lesson on clauses beginning with si.

Usually, when we think of verb tenses, we think of past, present and future. However, there's another tense, the conditional tense, that doesn't fit neatly in any of those categories. Sometimes known in Spanish as the futuro hipotético, it is usually the equivalent of the using the auxiliary verb "would" in English to refer to a hypothetical action.