Sank or Sunk: Sink's Past Tense, and Why Sunk Is Taking Over

You're doing dictation practice on a narrative passage. The speaker lets out a sentence, you write it down as "My heart sang when I saw it", and reading it back it looks like a cheerful sentence. The real sentence was "My heart sank when I saw it", and it says the exact opposite. A final /k/ sound drops out before a consonant, and what's left lines up exactly with another real word. Quick answer first: the simple past of sink is sank, and the past participle is sunk. The V-ing form is sinking.

Sink is hard in two places. First, its three forms differ by only one short vowel — sink, sank, sunk — and Vietnamese has no separate slot for any of those three vowels, so to a new learner's ear they collapse into almost one sound. Second, sunk is gradually creeping into sank's spot in speech: "The boat sunk" is a sentence you'll hear a lot from native speakers, but written down it still gets marked wrong.

This article goes through the whole chain: the form table for sink, the i-a-u chain it belongs to, the boundary between sank, sunk and sunken, the matter of sunk encroaching and how you should handle it, the phrases sink lives in beyond the literal meaning of a boat going under, and how these three forms sound when native speakers talk at normal speed.

• The form table for sink, and the i, a, u chain
• Where sank, sunk and sunken each stand
• Hearing sank and sunk in real speech
• Common phrases with sank and sunk
• Mistakes Vietnamese learners often make with sink
• Quick exercise
• Frequently asked questions

The form table for sink, and the i, a, u chain

Five forms, fitted neatly into one table. The phonetic column follows American pronunciation; British pronunciation for this verb is almost identical.

Form	Word	Pronunciation	Short example
Base form (V1)	sink	/sɪŋk/	Stones sink in water.
Third person singular	sinks	/sɪŋks/	The raft sinks slowly.
Simple past (V2)	sank	/sæŋk/	The ferry sank at dawn.
Past participle (V3)	sunk	/sʌŋk/	It has sunk already.
Present participle	sinking	/ˈsɪŋkɪŋ/	The boat was sinking fast.

Looking at the table, you can see right away that the change sits neatly in one letter in the middle of the word. s, n, k stay put across all five rows. Only the vowel moves: i becomes a becomes u. This is the easiest kind of irregular pattern in English to remember, and also the hardest to hear, because all the tense information gets crammed into exactly the shortest part of the word.

sink isn't alone. It belongs to a fairly crowded chain: drink becomes drank becomes drunk, sing becomes sang becomes sung, swim becomes swam becomes swum, ring becomes rang becomes rung, begin becomes began becomes begun, shrink becomes shrank becomes shrunk, spring becomes sprang becomes sprung. The whole group shares one mold: vowel i for present, a for simple past, u for participle.

What's worth noting is that this chain is wobbling in a few spots, and sink is one of the wobbliest. In everyday speech, a lot of native speakers use sunk straight through for the simple past too: "The boat sunk". Dictionaries record this usage as a second accepted form, while writing guides still treat sank as the only standard form in that slot. shrink is the same way with shrunk, and so is spring with sprung.

For a learner, the neatest way to handle this is to pick the safe side. Use sank for the simple past and sunk for the participle, and no one will ever mark you wrong for it, whether on a test or in a work email. When it comes to listening, though, you need to be mentally prepared that a speaker may produce sunk right where you're expecting sank, and that isn't you mishearing. A few verbs from the same chain are worth reading through in one go: the past tense of drink, because drunk also carries along a whole adjective meaning intoxicated, the past tense of sing, because sang is exactly the word your ear tends to mistakenly transcribe when you hear sank, and the past tense of swim, because swum is a form almost no one can ever remember. If you want to start not from a single verb but from the whole tense system, begin with the English grammar article.

Where sank, sunk and sunken each stand

The neatest rule: sank stands alone, sunk always needs have, has, had or be in front of it, and sunken never functions as a verb at all. Three words, three positions, and the simple-past position is the only one with any real dispute.

Sentence	Right or wrong	Why
The ferry sank at dawn.	Correct	Simple past, with a clear time marker
The ferry has sank.	Wrong	After has you need the participle sunk
The ferry has sunk.	Correct	Participle follows has
The ferry sunk at dawn.	Heard often, but avoid in writing	Very common in speech, but still marked wrong on tests
The ship has sunken.	Wrong	sunken only works as an adjective, not as a participle
Did the boat sank?	Wrong	After did the verb reverts to base form: sink

The fourth row is the most worth discussing in the whole table. It isn't wrong the way goed or sinked is wrong — that is, it isn't a made-up form. It's a real form, one native speakers use regularly, and if you write it down during a dictation exercise, you've correctly transcribed what was actually said. It's only when writing a sentence of your own that you should pick sank, since that's the form no one will ever flag as an error.

Sunken, on the other hand, is a different matter entirely. It used to be the participle of sink; nowadays it survives only as an adjective, and it only ever comes before a noun. The six sentences below sort the three words into three distinct slots.

Sentence	Real meaning
The boat sank in ten minutes.	The boat sank, recounting a completed event
The boat has sunk.	The boat is sunk now, and that state is a matter of the present
Divers photographed a sunken ship.	The wrecked ship is lying on the bottom; this is a descriptive adjective
He had sunken eyes.	Deep-set, hollow eyes; only the adjective works here
The living room has a sunken floor.	A floor lower than the rest, an architectural detail
Sunk costs should not drive the decision.	Money already spent and unrecoverable, a fixed term

The last row shows that sunk can also come before a noun, but only in a handful of set phrases like sunk costs that have hardened into fixed expressions. In most other cases, the adjective you need is sunken. There's no rule you can derive this from — it's simply a matter of habit tied to each specific phrase.

Hearing sank and sunk in real speech

This is the part no conjugation table ever covers, and it's also the part that decides whether you transcribe correctly or not. On paper, sink, sank, sunk are clearly distinct. In speech at normal speed, all three are thin, and two out of the three crash straight into two other real words.

The entire difference comes down to one short vowel. /ɪ/, /æ/, /ʌ/ sit very close to each other, and Vietnamese has no separate slot for any of the three. Beginners tend to collapse all three into one sound close to i or to ă, so sink, sank, sunk all land in the same spot in the ear. This is a root-level weakness, and it can't be fixed by learning more rules.

The n in sink isn't the Vietnamese n sound. It's /ŋ/, produced at the back of the tongue, closer to the ng sound in Vietnamese. If you pronounce it to yourself as /sɪn/, your ear will go looking for a sound that isn't actually there.

The final /k/ sound drops when the next word starts with a consonant, and that's the deadly spot. Losing the /k/ turns sank into sang, sunk into sung, and both of those are real words, belonging to the verb sing. "My heart sank when I saw it" and "My heart sang when I saw it" are both standard English sentences, with exactly opposite meanings.

Before a vowel, the /k/ doesn't drop — it slides onto the following word. "sunk in" becomes one block, "sun-kin", "sank into" becomes "sang-kintu". There's no gap in the sound, so anyone splitting words by eye will cut in the wrong place and lose the word entirely.

After have or has, the auxiliary is nearly invisible. "It has sunk in" in real speech is "it's sunk in", leaving just a single /s/ sound stuck onto the end of it. Miss that piece and you'll write down "It sunk in" — and, ironically, that sentence still sounds plausible, since sunk is already encroaching on the simple-past slot anyway.

think and sink are a pair unique to Vietnamese speakers. The /θ/ sound at the start of think doesn't exist in Vietnamese and gets replaced with /s/ or /t/ very often. When you yourself pronounce "I think so" as "I sink so", your ear also merges those two words when listening, and a sentence like "I think it sank" turns into a string of sound that can't be pulled apart.

The table below places the same sentence in three states: written down, sounding out loud, and slipped in transcription. The middle column records exactly what reaches the ear, not textbook phonetic transcription.

Real sentence	Sounds like	Learners often transcribe as
My heart sank when I saw it.	mai hart sang wen ai so-rit	My heart sang when I saw it.
The boat sank without a trace.	thuh bout sang withou-ta treis	The boat sang without a trace.
It still hasn't sunk in.	it stil haznt sun-kin	It still hasn't sung in.
Prices have sunk to a new low.	praisiz-uv sung tu a nu lou	Prices have sung to a new low.
I think it sank pretty fast.	ai thing-kit sang-k preti fast	I sink it sang pretty fast.
He sank into the armchair.	hi sang-kintu thi armchea	He sang into the armchair.

The third column contains almost only one type of error, and that is what makes this verb frightening. Four of the six lines are the same mechanism: the final /k/ sound drops before a consonant and the word falls straight into some form of sing. Line five adds an initial consonant error with /θ/, while lines three and six show the flip side: when /k/ links to the following word, the word boundary shifts and the transcriber cuts in the wrong place.

On WELE, a dictation listening session lets you see this chain run through step by step. Each sentence you hear gets transcribed exactly as heard, then the scoring pinpoints precisely which word is off. When the word marked is sank but you wrote sang, you get a piece of information that reading a verb conjugation table never gives you: your ear isn't registering the final stop sound after /ŋ/. That same weak point will also trip you up on bank turning into bang, thank into thang, drink into dring.

You remember from the moment you see exactly where you transcribed wrong. Finish reading the five-line table at the start of this article, and ten minutes later you still know sank is the past tense of sink, but your ear hasn't changed at all. Miss a sentence in transcription and then hear again exactly where you missed it, and the next time you encounter it, your ear already has a marker in place. If you want to know why these sounds disappear, the article on connected speech covers the mechanics of sound-swallowing and linking across a whole sentence, and why that isn't your ear's fault. To practice on real voices, there are podcasts in the library, and every episode comes with a transcript to check against.

Common phrases with sank and sunk

If you only remember sink in the sense of a ship sinking, you'll miss most of where it actually shows up. In everyday conversation, sink talks about feelings dropping, information settling into your head, and money going into something you can't pull back out. The twelve lines below are written in the past or participle form so you get used to seeing them that way.

Phrase	Meaning	Example
sink in	To settle into your head, to be understood after a while	The news finally sank in on the drive home.
one's heart sinks	To feel one's heart drop, to feel let down	My heart sank when I saw the queue.
a sinking feeling	A bad premonition, a feeling of dropping	I had a sinking feeling about the numbers.
sink or swim	Fend for yourself, no way back	They were left to sink or swim.
sink into	To sink into, to drop into	He sank into the armchair and closed his eyes.
sink back	To lean back	She sank back against the wall.
sink down	To slump down	He sank down onto the step.
sink to a new low	To drop to an unprecedented low	Sales have sunk to a new low.
sink a ship	To sink a ship	A single torpedo sank the ship.
sink money into	To pour money into something	They sank a lot of money into that store.
sunk costs	Costs already spent, unrecoverable	Sunk costs should not drive the decision.
everything but the kitchen sink	To bring absolutely everything along	She packed everything but the kitchen sink.

The first line of the table is the phrase you'll run into the most, and it has its own grammatical habit. sink in almost always shows up in the perfect tense with a negative word: "It hasn't sunk in yet", "It still hasn't sunk in". People use it to say that their head has heard the news but their heart hasn't caught up to believing it yet, so the sentence naturally leans toward the present perfect.

The sunk costs line is worth remembering if you work with business documents. This phrase is fixed — it doesn't change to sunken costs or sank costs — and it usually comes with a piece of advice: don't let money already spent decide your next step. In podcasts about economics or management, this is one of the densest recurring phrases.

Mistakes Vietnamese speakers commonly make with sink

Sinked. The root of this mistake is the habit of treating -ed as a universal past-tense switch. sink never conjugates by the rule. There's only sink, sank, sunk.

Using sank after did. "Did the boat sank?" is a mistake that shows up right when you've just remembered sank and remembered it too well. did already carries the past-tense meaning, so the verb goes back to its base form: "Did the boat sink?".

Has sank instead of has sunk. This is the reverse of the common native-speaker mistake, and it's the mistake of a learner who has memorized the table but hasn't gotten used to where each form goes. After have, has, had, only sunk is used.

The boat sunk in writing. You'll hear this sentence a lot, including from presenters and news writers. Hearing it doesn't mean it's usable everywhere. In exams and formal writing, the simple past should be sank, because that's the form no one can fault.

Using sunken as a verb. "The ship has sunken" is wrong. sunken only survives as an adjective and only goes before a noun: a sunken ship, sunken eyes, a sunken floor. After have, has, had, it's always sunk.

Pronouncing think as sink. The initial /θ/ sound doesn't exist in Vietnamese and gets replaced by /s/ or /t/ out of habit. The consequence doesn't stop at the listener misunderstanding — it also damages your own listening ability, because your ear can only distinguish sounds that your mouth has already learned to distinguish. This is a pair worth the separate effort to practice, since think is one of the densest words in spoken English.

Quick exercise

Eight sentences, fill in sink, sank, sunk, or sunken. Do all the sentences yourself first, then check the answers below.

1. The ferry ______ in less than twenty minutes.
2. The news still hasn't ______ in.
3. Did the boat ______ before help arrived?
4. My heart ______ when I saw the queue at the counter.
5. Sales have ______ to a new low this quarter.
6. Divers photographed a ______ ship off the coast.
7. They ______ a lot of money into that store last year.
8. ______ costs should not drive the decision.

Answers: 1. sank. 2. sunk. 3. sink. 4. sank. 5. sunk. 6. sunken. 7. sank. 8. Sunk.

Sentences 6 and 8 are worth pausing on. Sentence 6 needs an adjective before a noun, so it must be sunken. Sentence 8 also comes before a noun but uses sunk instead, because sunk costs is a fixed phrase. These two sentences show that the sunken-versus-sunk split has no rule you can derive — it's a matter of habit for each individual phrase, and the way to remember it is to encounter them enough times in real sentences.

Frequently asked questions

What is the past tense of sink?

The simple past of sink is sank, and the past participle is sunk. sank acts as the main verb on its own in a simple past sentence, while sunk always follows have, has, had, or be.

Sank or sunk, which one is correct?

Both are correct in their own position. With no auxiliary verb in front, use sank. With have, has, had, or in a passive sentence, use sunk. In the simple-past position specifically, you'll hear a lot of people say sunk, but the safe choice when you write it yourself is still sank.

How is sunken different from sunk?

sunk is the participle, used in the perfect tenses and passive sentences. sunken is an adjective, and only goes before a noun: a sunken ship, sunken eyes, a sunken garden. The sentence "The ship has sunken" is wrong; the correct form is "The ship has sunk".

What does sink in mean?

It means a piece of information takes a while before it truly settles into your head. "It hasn't sunk in yet" is what people say when they've just received big news that their heart hasn't caught up to believing yet. This phrase almost always goes with the present perfect tense and usually comes with an added negative word.

Why does sank get heard, or transcribed, as sang?

Because the final /k/ sound drops when the next word starts with a consonant, and what's left lines up exactly with sang, the past tense of sing. Both are standard English sentences, so you have no signal to make you suspicious — and "My heart sank" and "My heart sang" are complete opposites in meaning.

How long does it take to study sank and sunk before you can catch them in fast speech?

As far as the rule goes, one proper sitting is enough. The ear part depends on your current listening level, and the most realistic way to measure it is to transcribe a few passages containing words ending in /ŋk/ and see where you still miss. You need a starting point, and the listening level test gives you that.

You can finish reading the table of sink's forms in twenty seconds, and that's the easiest part of this page. The rest — the fact that one dropped /k/ sound sends sank falling straight into sang — only really sinks in once you mishear it and then see where you transcribed it wrong. Pick a short passage and try listening dictation on a sentence with sank or sunk printed in it, then go back to the table at the top of the article and see if it still looks as dry.