Present Tense

The vast majority of German verbs are regular. To conjugate one, you take the infinitive, strip the -en ending to expose the stem, and then attach the ending that matches the subject. Use lernen (to learn) as your reference:

Two of these forms are worth noting: wir and sie/Sie always end in -en, which is identical to the infinitive. For any regular verb, you can read those two forms straight off the dictionary entry without thinking.

The regular endings apply to almost every verb, but some stems need a small tweak before they can take them. The underlying logic is always pronunciation: German avoids consonant clusters that are genuinely difficult to say.

A significant number of common German verbs change the vowel inside their stem when used with du or er/sie/es. Every other form — ich, wir, ihr, sie/Sie — stays completely regular. The verb behaves normally everywhere except those two slots.

There are two patterns to recognise:

There is no rule that predicts which verbs change their vowel — you simply learn each one as you encounter it. Most dictionaries and vocabulary lists flag these verbs explicitly. When you see a verb marked as a vowel changer, make a note of what the changed form looks like; it will appear constantly in real German.

These three verbs are fully irregular — they do not follow the standard endings and need to be learnt as standalone forms. That is the less appealing part. The more useful part: they appear in almost everything you say, so you will absorb them quickly through sheer repetition.

Sein looks like three different verbs stitched together — historically, it was. It draws from three separate Latin roots, which is why bin, ist, and sind share almost nothing. Haben is mostly regular except in the third person singular, where hat drops the b from the stem. Werden is a vowel changer on top of its other quirks: the stem shifts from werd- to wirst and wird in the singular.