When I was studying Latin, I would learn the conjugation of each verb by memorizing its principal parts (for example, "amo, amare, amavi, amatus"). In Spanish, are there any principal parts of a verb that can be memorized in order to conjugate every form of a regular verb? According to this Yahoo Answers post (which clearly isn't a reliable source), the principal parts of a Spanish verb correspond directly to those in Latin, but I'm not sure if this correct. Do Spanish verbs have principal parts that can be used to conjugate them, like Latin verbs?
Spanish regular verbs have -ar, -er or -ir endings. If you drop those endings, you get a "principal" part or "stem" that you can conjugate.
Some of these principal parts change the stem in certain conjugate forms. For instance, tener has ten-go and ten-emos in the first person forms, but the stem changes to tien-es, tien-e and tien-en in the second and third person forms (the second person plural is teneis, and retains its stem).
Well, conjugations change depending on the category of the verb (AR, ER, IR verbs).
This is an example for the present tense:
However, there are irregular verbs!