'd
The contraction 'd can stand for any of three different words: did, would, had. Fortunately, its correct interpretation can easily be determined from the words around it.
did
1 After question words such as where, when, why, etc., 'd stands for did*: Where'd you go? means Where did you go?
____________
*Note that because of this, after a question word, the conditional would can only be expressed with the full form would, since 'd always stands for did. In other words, Where'd you go? would never be taken to mean Where would you go?Amy: I had my first date with Evan last night.
Nina: Oh yeah, where'd he take you?
Amy: To that new Thai place on Palm Street.
Nina: Nice! What'd you wear?
Amy: A nice black dress.
Nina: What time did you get home?
Amy: None of your business! hahahaha
had
2 Before a past participle such as seen, given, gone, etc., 'd stands for had and is used to form the past perfect.
Note that it'd follows the same pronunciation patterns as what'd above; it's pronounced either [ɪːd] or [ɪ́ɖɪd].
Did he think it'd helped?
[dɪɖiθɪ̀ŋk ɪːd.hɛ́ɫpt] or [dɪɖiθɪ̀ŋk ɪɖɪd.hɛ́ɫpt]
In this snippet, note that all the instances of 'd/had are followed by a past participle.
____________
I ran into Mark this morning. I didn't realize it'd been so long since I'd last seen him. We'd actually been pretty good friends in school. He told me he'd moved to England and hăd gotten married and divorced... it's incredible how much someone can change in ten years.
Interestingly enough, although the past perfect had can be contracted to 'd, a lot of speakers tend to keep the word had separate in the past perfect when the pronoun in front of it has a primary or secondary stress. In this case, the vowel is reduced to a very short [ɛ] and the initial [h] is retained. This usually happens when had follows the subject of the sentence, which, as the topic, has a secondary stress: [hᵋd].
Bart knew us. Wè hăd wòrked for his fáther.In this example, we, as the first word in this sentence, isn't completely unstressed. However, in the following example, we have a series of unstressed words (indicated by the dot), including we, and thus the contraction we'd sounds more natural:
Bart knew us frọm whẹn wẹ'd wòrked for his fáther.This is from 002 Birdwatching, where I talk about photographing birds in my local park.
____________
Naturally, I couldn't get too close to them, but I could zoom in and get some pretty nice shots. This was in early spring, so a lot of the birds had chicks. Within two weeks, I hăd photographed a good 25 different kinds of birds.