Principal Parts

All verb have four principal parts: infinitive, present participle, past, past participle. Different principal parts can assume different roles in a sentence.

Principal Parts of Regular Verbs

Regular verbs add -ing to the infinitive form to create the present participle, sometimes doubling the final consonant of the infinitive stem or dropping its final e: Thus tap becomes tapping, and bake becomes baking. To create the past and past participle forms (which are identical in regular verbs), the verbs add -ed to the infinitive stem. Again the stem sometimes doubles its final consonant or drops a final e before adding the -ed suffix. Thus tap becomes tapped, and bake becomes baked.

infinitive	present participle	past	past participle
bake	baking	baked	baked
tap	tapping	tapped	tapped

Below is a table of the irregular principal parts.