This change of the ending of a verb is called conjugation.

Verbs are used to talk about what is happening and when those things are happening. For example, to talk about something that is happening at this moment or about something that is about to happen in the future, Germans use the so-called Präsens.

Like in many languages there are regular and irregular verbs. It sounds worse than it is. The regular verbs in the Präsens are conjugated exactly as you can see in the example of machen above. All you have to do to find the right form is the following:

1. Take the infinitive of the verb (e.g. machen) and drop the -en ending. What’s left is called "Stamm" in German (=root, literally: stem)
2. Add the personal ending (those marked red in the table above) that fits the person doing the action and you’re done.

The result is called the finite (=finished) verb as opposed to infinite (not finished) verb.

Die Extrawurst | the Special Sausage

At times you’ll have to add an extra -e at the end of the root to make the verb pronounceable. This is usually the case when the stem ends in -d or -t. Take a look at arbeiten (=to work) and finden (=to find):