Theorie:
Study the information about the formation of the past perfect.
| Affirmative | subject + had + past participle | You had decided what to do by 5 o'clock yesterday. |  |
| Negative | subject + had + not + past participle | You had not decided what to do by 4 o'clock yesterday. |  |
| Interrogative | had + subject + past participle | Had you decided what to do by 6 o'clock? |  |
Past participle
Irregular verbs | You have to know all the forms of the irregular verbs very well. For the past perfect you need the form of the verb which can be found in the 3rd column of the table of irregular verbs | go – went – gone |
| Regular verbs | add -ed | work – worked |
Sometimes there are exceptions in spelling when adding -ed:
| Consonant after a short, stressed vowel at the end of the word | double the consonant: | stop – stopped swap – swapped |
| In British English | double one -l at the end of the word: | travel – travelled |
| One -e at the end of the word | add only -d: | love – loved save – saved |
Verbs ending in -y | verbs ending in 'y' preceded by a vowel (a, e, i, o, u); add -ed: | play – played |
| change 'y' to 'i' after a consonant; then add -ed: | worry – worried |
Quellen:
www.haganblount.com
www.grammar-monster.com