I would must be followed by an infinitive without to ( or perfect infinitive as in I would have gone). I had must be followed either by an object (a noun phrase, e.g. I had a little lamb, in which meaning it is rarely contracted) or by a verb's past participle. So it's (almost) always possible to distinguish between them by analyzing the words that follow.

Examples:

I'd go. (go = infinitive => 'd = would)

I'd had. (had = participle => 'd = had)

The only ambiguous case is when the verb's infinitive coincides with its participle.

I'd put. (could be would or had)

But these cases are rare and the meaning can be deduced if more context is provided

Answer from Armen Ծիրունյան on Stack Exchange
People also ask

What are contractions?
Contractions are two or more words that are combined and shortened to save time. Typically, you can identify a contraction by the apostrophe, as with isn’t or they’ve—but don’t confuse contractions with possessive nouns, which also use apostrophes.
🌐
grammarly.com
grammarly.com › blog › grammar › contractions
What Are Contractions in Writing? Definition and Examples | Grammarly
What are some examples of contractions?
Some of the most common contractions in English include can’t, it’s, they’ve, what’s, and would’ve.
🌐
grammarly.com
grammarly.com › blog › grammar › contractions
What Are Contractions in Writing? Definition and Examples | Grammarly
When should you use contractions?
Contractions are considered informal, so they should not be used in formal writing like academic papers.
🌐
grammarly.com
grammarly.com › blog › grammar › contractions
What Are Contractions in Writing? Definition and Examples | Grammarly
🌐
Cambridge Dictionary
dictionary.cambridge.org › us › grammar › british-grammar › contractions
Contractions - English Grammar Today - Cambridge Dictionary
+ object + infinitive or -ing Help somebody (to) do Look forward to Stop + -ing form or to-infinitive Verb patterns: verb + infinitive or verb + -ing? Verb patterns: verb + that-clause Verb patterns: with and without objects Would like Would rather, would sooner Phrasal verbs and multi-word verbs ... Get passive Have something done Passive: forms Passives with and without an agent Passive: uses Passive: other forms Passive: typical errors ... Can Could Could, may and might Dare Had better May Might Modality: forms Modality: meanings and uses Modality: tense Modality: other verbs Modality: other modal words and expressions Must Need Ought to Shall Should Will Would
🌐
YouTube
youtube.com › learn english with emma [engvid]
Speak English Naturally with WOULD contractions: I'D, YOU'D, HE'D... - YouTube
Want to sound more like a native speaker? In this lesson, I will teach you many "would" contractions that native speakers use frequently without thinking abo...
Published   June 15, 2015
Views   665K
🌐
WordReference
forum.wordreference.com › english only › english only
It'd = It would? [Contraction with 'would'] | WordReference Forums
January 12, 2017 - Well, the term "contraction" to me means "written contraction". If we're talking about speech, then unstressed "would" and "had" can, in the appropriate environments, become either /əd/ or /d/.
Find elsewhere
🌐
Speakspeak
speakspeak.com › resources › english-grammar-rules › various-grammar-rules › apostrophe-d-had-or-would
‘d = “had” or “would”
May 15, 2018 - The contraction I’d can mean “I would” or “I had”. Here are some similar examples: You’d = you would or you had He’d = he would or he had She’d = she…
🌐
Gymglish
gymglish.com › homepage › online english lessons › grammar rules: learn and improve - gymglish › contractions: 'would' vs 'had'
Contractions: 'would' vs 'had': How and When to Use - Gymglish
The auxiliary verbs would and had are both contracted to 'd. How can they be distinguished? • Would is always followed by a verb in the infinitive without the to:
🌐
Grammarly
grammarly.com › blog › grammar › contractions
What Are Contractions in Writing? Definition and Examples | Grammarly
August 10, 2022 - Only certain words can be contracted: ... he/she/it, they), and modal verbs (can, will, might, must, should, would, could). Even though they represent multiple words, contractions act as a single word. Moreover, contractions all have a definite spelling, which means you can’t ...
🌐
Scribbr
scribbr.com › home › contractions (grammar) | definition & examples
Contractions (Grammar) | Definition & Examples
May 2, 2025 - Contractions are words or phrases that have been shortened by omitting one or more letters (e.g., “You’re”).
🌐
Quora
quora.com › Hed-is-a-contraction-of-he-would-Wouldve-is-a-contraction-of-would-have-Is-it-ok-to-write-hedve-as-a-contraction-of-he-would-have
'He'd' is a contraction of 'he would'. 'Would've' is a contraction of 'would have'. Is it ok to write 'he'd've' as a contraction of 'he would have'? - Quora
Answer (1 of 10): Thanks for the A2A, Barney. Yes, it is absolutely okay. I can see why people might think it looks a bit odd, with two apostrophes in quick succession, but it's perfectly right. In Jane Austen’s time they did this with contractions like “sha'n't” and “wo'n't,” but we don't do t...
🌐
GCFGlobal
edu.gcfglobal.org › en › grammar › contractions › 1
Grammar: Contractions
The apostrophe goes in its place, right between the n and t. Let's look at another example. You'll means you will. This contraction is missing two letters from the word will: w and i.
🌐
Quora
quora.com › Whats-the-meaning-of-I-d-Is-it-I-had-or-I-would
What's the meaning of I’d? Is it ‘I had’ or ‘I would’? - Quora
What is ('d) exactly used for? Does it mean "had," "did" and "would"? Is it any sort of contraction? It is a contraction that stands for both 'had', and 'would'. The syntactic context w...
🌐
Grammarplainandsimple
grammarplainandsimple.com › home › parts of speech › 839. contractions with would
839. Contractions with Would - Grammar, Plain and Simple
April 18, 2024 - Certain pronouns can be combined with the verb would. I would = I'dyou would = you'dwe would = we'dthey would = they'd I would help you if I could.I'd help you if I could. We would make a good team.We'd make a good team. Use the verb would to make contractions. ▶Now you try it.
🌐
Quora
quora.com › If-would-ve-could-ve-and-should-ve-are-proper-English-contractions-why-aren-t-wouldn-t-ve-shouldn-t-ve-and-couldn-t-ve
If would’ve, could’ve, and should’ve are proper English contractions, why aren’t wouldn’t’ve, shouldn’t’ve, and couldn’t’ve? - Quora
Answer (1 of 83): I use those words (wouldn’t’ve, shouldn’t’ve and couldn’t’ve) all the time, usually only in speech. But that is only because my writing (although I flatter myself that I try to mime the spoken word) does not often use those words, (Too hard to type for a lazy like ...