The past perfect tense

The positive - make it with 'had' + the past participle (usually made by adding 'ed' to the infinitive, but a few verbs have irregular past participles)

The short form for 'had' is 'd. 

• I had been (I'd been)
• You had gone (you'd gone)
• She had met (she'd met)

(Be careful not to confuse it with 'would'. Would is followed by the infinitive - 'I'd go', whereas had is followed by the past participle - 'I'd gone').

For the negative just add 'not':

• I had not been (I hadn't been)
• And to make a 'yes / no' question put 'had' before the subject:
  • Had I come?
  • Had you eaten?
  • Had she gone?
  For 'wh' questions put the question word at the beginning:
• When had I come?
• Why had you eaten?
• Where had she gone?
• When had it rained?
• How had we met?

Finally here's an exercise about past perfect questions. Go to:  http://www.montsemorales.com/gramatica/PastPerfect1.htm