One of the most important aspect of English, about speaking English are the irregular verbs. No matter how hard you'd try to speak using other parts, ways, if you don't know these verbs you don't know English. I'm saying this so easily because I can surely explain it: If you take a closer look to this text you'll find a lot of actions, a lot of verbs. Now, I try to use the simple present in most of my articles for giving a fresh attitude and a present way, face to face, sort of speak, closeness and an easier way to interpretate my pieces of advice. No matter the time used, verbs are still existing.
It is the verbs that put the mark on what's well or not so well written. Adjectives, pronouns or nouns are the ones creating a contour and the verbs are the fine touch (as I like to call it). The most common way to learn the verbs is to use them in everything that you do. When you have a busy day try to squeeze a little fun exercise by using short sentences inside your head "i'm writing an e-mail, i wrote a mail to my boss". Don't hesitate to search the verbs in a dictionary and understand exactly the meaning. Nothing will be in its order unless you understand perfectly the match, the meaning and the expressions.
A simple piece of advice: don't learn like in school. Read a book, read on cereals bags, it doesn't matter where, just read, choose a text and then try to fully understand all written. The most important thing is to become aware of their importance and try to structure them inside your head instead of creating a stress, a disaster out of it.