When a strong verb in German is becoming weak, language dictionaries often show it by adding the weak past tense in parentheses, like this: "backen / buk (backte) / gebacken." This can be misleading, because many native speakers wouldn't write "buk" or "backte" -- they'd just avoid the problem by using the Perfekt: "hat gebacken." This should be your approach too. For the past forms that we've put in brackets, just avoid them and use the Perfekt, even in writing.

Where a present or participle form has weakened, the forms are more interchangeable, but we've tried to put the less common one in parentheses.

This list does not include auxiliary, modal or mixed verbs. It's better to learn those separately, since there are so few of them and they each have their own quirks. We cover all their forms in sections V.3 and V.4.

Some people find it easier to learn the strong verbs when they're sorted into groups by vowel pattern. Click here for the list in that format.