Knew or Known: The Past Tense of "Know," the Silent K, and Three Homophone Pairs

You're doing dictation practice on a dialogue. The speaker drops a sentence, you write it down as "I new that already," and the second word gets marked wrong with a red underline. The real sentence was "I knew that already." Your ear heard it one hundred percent correctly — those two words sound exactly the same in an American accent — but you picked the wrong spelling. Quick answer first: the past simple of know is knew, and the past participle of know is known. The -ing form is knowing, the third person singular is knows.

The hard part of know sits in two places that have nothing to do with the conjugation table. First, the k at the start of the word is completely silent, in all four forms, so know sounds the same as no, knew sounds the same as new, knows sounds the same as nose. Taking dictation on a verb whose entire family has homophones is a special kind of hard. Second, know pairs with the present perfect in a way that Vietnamese doesn't have, and that's where learners make the most mistakes when talking about a relationship that has lasted a long time.

This article goes through all of that: the form table for know and its relatives grow, throw, blow, why the k is silent, the boundary between knew and known, three pairs of homophones around know, and — the most important part for listening practice — how these forms sound when a sentence runs at real speed.

• The forms of know, the silent k, and the grow, throw family
• When to use knew, when to use known
• Hearing knew and known in real speech
• Common phrases with knew and known
• Mistakes Vietnamese learners often make with know
• Quick exercise
• Frequently asked questions

The forms of know, the silent k, and the grow, throw family

Five forms, fit into one table. The phonetics follow the American accent, with British differences noted alongside where they're significant.

The first thing worth pointing out isn't in the spelling column, it's the fact that the phonetics column has no k at all. The k in know, knew, known, knee, knife, knock, knot, knight is completely silent. This isn't an arbitrary convention. Up until around the 17th century, English speakers still pronounced the whole kn cluster at the start of the word, meaning know really did sound like k-now. After that, the initial consonant cluster gradually simplified in speech, while the spelling froze in place from the age of the printing press. The k you see today is a fossil of a pronunciation that's long dead.

In terms of shape, know belongs to the group that shifts its vowel through the ow, ew, own pattern. grow becomes grew then grown. throw becomes threw then thrown. blow becomes blew then blown. fly becomes flew then flown — spelled differently, but the same sound pattern. This is one of the most predictable groups among irregular verbs: remember grow, grew, grown, and you've got the shape of the whole group.

One small difference between know and its groupmates lies in the vowel of the V2 form. grew, threw, blew, knew all have the /uː/ sound, but knew specifically still carries an extra /j/ sound in front of it in standard British pronunciation, making it /njuː/. Americans drop that /j/ sound. This is exactly why knew and new are complete homophones in the American accent, while in the British accent both carry the /j/ so they still match each other. Either way, the pair still sounds the same.

There are three verbs worth reading alongside this one, each for a different reason. The past tense of grow is the standard pattern for the whole ow, ew, own group — learn it and you no longer need to memorize the shape of know separately. The past tense of fly shares the same sound pattern but a different spelling pattern, which shows the limits of learning by spelling alone. The past tense of hear is worth reading for an entirely different reason: hear and know are two stative verbs that often get misused in the continuous tense. For the bigger picture, the article on English grammar is where the tenses connect to each verb group.

When to use knew, when to use known

The simplest rule: knew stands alone as the main verb of the sentence, known always needs have, has, had, or a form of be in front of it. The trap is that those very auxiliaries often get contracted down to just a single consonant stuck onto the subject.

Rules done, now for the part that actually causes trouble. The mistake Vietnamese learners make most with know isn't choosing between knew and known, it's choosing the tense. The sentence "Tôi biết cô ấy mười năm rồi" (I've known her for ten years), translated word for word into English, comes out as "I know her for ten years," and that sentence is wrong. Vietnamese lets the word "rồi" carry the time element, English makes the verb carry it, so it has to be "I have known her for ten years."

This is the general rule for any action that started in the past and still continues now, but know is where it shows up most clearly, because knowing someone is a lasting state in the most literal sense. The six pairs below make clear the gap between the choices.

The second line is worth pausing on because it carries an implication that learners don't mean to say. "I knew her" in English carries the tone that the relationship has ended, sometimes because the other person moved away, sometimes for a heavier reason. If you still know the person and you say this sentence, the listener will get the wrong idea. To say you've known someone a long time and still do, you must use have known.

The last two lines show that known in the passive splits into two different meanings depending on the preposition. known for means famous because of something. known as means called by a certain name. Both come up a lot in academic listening material and in podcast guest introductions, and they can't be swapped for each other.

Hearing knew and known in real speech

This is the part the conjugation table never touches, and with know it matters especially because the trap isn't that you can't hear it. You hear it very clearly. The problem is that the sound you hear maps onto two different spellings, and picking the wrong one throws off the meaning of the whole sentence.

There's nothing to hear for the letter k, in any form. know starts with exactly one consonant, /n/. If you're waiting to hear a light puff of air at the start of the word, you're waiting for something that doesn't exist. In a dictation, the decision to write know or no rests entirely on the meaning of the sentence.

knew and new are complete homophones. In the American accent both are /nuː/, in the British accent both are /njuː/. There's no sound clue that separates them. The only way is to look at position in the sentence: knew is a verb so it comes after the subject, new is an adjective so it comes before a noun or after to be.

knows sounds the same as nose, no also matches know. "She knows" and "her nose" differ only in the word that comes before. "I know" and "I, no" differ only by a comma, something that doesn't exist in sound. This is why short sentences with know are so easy to mis-transcribe even when you hear every sound clearly.

didn't know contracts down to two syllables. "I didn't know" in real speech comes out almost like "ai din-no". The t of didn't disappears completely, and the final d also blurs into the n of know. Learners write it down as "I did no" or "I didn't no", and both are wrong.

known after an auxiliary is left with only one consonant to guide you. "We have known" becomes "we've known", and the only part still audible is the /v/ sound. "He has been known" becomes "he's been known". Miss that /v/ and your transcript turns into "we known" — a sentence that's grammatically wrong but still sounds smooth to your ear.

you know works as a filler, don't transcribe it like a verb. In real conversation, "you know" turns up densely, like a filler sound plugging gaps, contracted to "y'know" or "ya-no", said very fast with no stress. It carries no meaning. Learners new to listening practice often stop to analyze it and end up missing the whole sentence that follows.

Below are sample sentences, the actual sound, and where learners tend to mis-transcribe. The middle column is the sentence as it sounds in real life, not a standard phonetic transcription.

Look at the third column and you'll see the mistakes here are quite different from mistakes with other verbs, and that's the most notable thing about know. Row one, row four and row six are pure homophone errors: the ear catches it right, the wrong word gets picked. Row two is an error from a compressed negative phrase, both didn't and know break down together. Row three is a function-word error, the /v/ of have gets swallowed and drags the whole perfect tense down with it. Row five is a final-sound error, the n of known drops off, which makes the sentence grammatically wrong.

In a dictation listening session on WELE, the difference between these types of errors shows up very clearly. You listen to the sentence then write it down as is, and the grading handles spotting the words that are off. When the word marked wrong is knew but you wrote new, the diagnosis isn't "your ear is weak" but "you haven't used the sentence's grammar to pick the right spelling". Listening again a hundred times won't fix this type of error, because the two words are pronounced the same to begin with.

The errors in row two and row three are the opposite — they're genuinely ear errors, and listening again works right away. What's useful about transcribing sentence by sentence is that you can tell these two types apart instead of lumping them into one vague feeling that your listening is bad. A verb conjugation table doesn't give you that information, but a marked-up transcript does.

If you want to understand why these sounds disappear rather than assume your listening is bad, the connected speech article explains the mechanics of sound-dropping and linking across whole sentences, not just know. And if you want to try it on real sentences, go to the podcast library — every episode has a transcript so you can check your work after each round of transcribing.

Common phrases with knew and known

know doesn't produce many phrasal verbs with prepositions, but it's rich in fixed expressions, and those fixed expressions are exactly what you run into every day in conversation. The table below mixes both types. The examples are written in the past or participle form so you get used to seeing them that way.

There's a detail worth noting in the first two rows. know about and know of sound almost alike, but the gap between them is very clear to a native speaker. know about a person means you have information about them. know of a person means you've only heard the name, a much lighter degree. In Vietnamese both come out as biết về, so learners often pick one at random and the sentence loses its proper nuance.

The know better row is also worth noting because it almost always shows up in the perfect form, in a reproachful tone. "You should have known better" means you should have known to avoid it. This phrase comes up a lot in films and in storytelling podcasts, and if you only translate it word for word, that reproachful meaning disappears completely.

Mistakes Vietnamese learners often make with know

knowed. This is the reflex of adding ed to every verb. know is never conjugated by the rule. There's only knew and known, no knowed, no knewed. In the same group there's also growed, throwed, blowed, all wrong for the same reason.

Did you knew. Once did appears, the tense is already taken care of, and the verb that follows goes back to its base form. "Did you know about the change?" is the correct version. This error tends to show up right when you're focused on remembering that the past tense of know is knew — and remembering it too well. In the same group there's also "didn't knew" and "did she knew".

I have knew. After have, has, had it must be the participle known. This is the reverse of the error above: learners remember knew and then use it everywhere that carries a past meaning. Pick "I knew" if there's a closed time marker, or "I have known" if the relationship still extends into the present.

I know her for ten years. This is the most common error in the whole group, and it isn't a conjugation error but a tense-choice error. Whenever a sentence has for or since attached to a span of time that extends to the present, the verb must be in the present perfect. "I have known her for ten years", "We have known each other since 2015".

Using know instead of know about. "Do you know the meeting?" sounds very odd to a native speaker, because when know takes a noun denoting an event, it needs about. The correct sentence is "Do you know about the meeting?". On the other hand, know a person or a place doesn't need about: "Do you know Hanoi?" is completely fine.

Writing no instead of know, new instead of knew, in listening exercises. This is a spelling error, but it wrecks the whole sentence, because no and new belong to entirely different word classes. The fix isn't in the ear but in rereading the sentence you just transcribed: if that spot calls for a verb and you wrote down an adjective or a negative word, the sentence is meaningless on its own. One read-through catches almost all of this type of error.

Quick exercise

Eight sentences, fill in know, knew, known or knows. Fill them all in first — the answer key is right below, saved for afterward.

1. I ______ the answer before she finished the question.
2. We have ______ each other since primary school.
3. Did you ______ about the schedule change?
4. She is ______ for her work on climate data.
5. Nobody ______ how to fix it at the time.
6. He ______ everyone in this building, ask him.
7. You should have ______ better than to send that.
8. As far as I ______, the office closes at six.

Answers: 1. knew. 2. known. 3. know. 4. known. 5. knew. 6. knows. 7. known. 8. know.

Let's pause a little longer on sentence 2 and sentence 7. Sentence 2 has since paired with a point in the past where the relationship still holds, so it has to be have known, not knew. Sentence 7 sits inside the phrase should have, and after have you always get a past participle, so it's known. If you slipped on these two, the section on knew and known in the middle of the article is worth another read.

Frequently asked questions

What is the past tense of know?

The simple past of know is knew, the past participle is known. These two forms are not interchangeable: knew serves as the main verb in a simple past sentence, while known always follows have, has, had, or a form of be.

Why does know have a k that isn't pronounced?

Because the pronunciation changed but the spelling didn't. Up until around the 17th century, the kn cluster at the start of a word was still fully pronounced in English. After that the cluster simplified in speech, while the spelling had already been fixed earlier. The same thing happened with knee, knife, knock, knot, knight.

Do knew and new sound the same?

Yes. In American accents both are /nuː/, in British accents both are /njuː/. There's no way to tell them apart by ear. You can only distinguish them by position in the sentence: knew is a verb, it comes after the subject, while new is an adjective, it comes before a noun or after to be.

Should you write I know her for ten years or I have known her for ten years?

It has to be "I have known her for ten years". When a sentence has for or since paired with a span of time that still extends to the present, English uses the present perfect. The sentence "I know her for ten years" is a word-for-word translation error from Vietnamese, and native speakers will find it broken.

How is known for different from known as?

known for means famous because of something, usually followed by an achievement or a trait: "She is known for her research". known as means called by some name, followed by a name or a title: "The area is known as the old quarter".

How long does it take to learn knew and known well enough to catch them in fast speech?

The rule is quick, you can remember it in one sitting. Picking the right written form between homophone pairs takes many real sentences, because it relies on the sentence's grammar, not on your ear. The most realistic way to measure it is to transcribe a few dialogues and see where you still fall short. A listening level test taken today will give you a benchmark to compare against in a few weeks.

You can read through the table of know's forms in thirty seconds, and that's the easiest part of this page. The rest, the fact that knew sounds the same as new and the fact that didn't know compresses down to two syllables, only really sinks into your ear and your hand once you mishear it and then see where you transcribed it wrong. Pick a short clip and try dictation practice on a passage with knew or known, then go back to the table at the top of the article and see if it still looks as obvious as it did before.