Choose is the present tense and rhymes with news: "I choose to walk", "choose a seat". Chose is its past tense and rhymes with nose: "last week I chose to walk". Same verb, different time — and the double o goes with the present, the single o with the past.
The core difference
This is not two words but one verb in two tenses. Choose covers now, always, and the future when a helping word is present. Chose covers a completed action in the past, standing on its own without a helper.
How to use each
- Choose: "I choose my battles carefully." "Choose whichever suits you." "They will choose a name before the birth." "He has to choose by Friday."
- Chose: "She chose the aisle seat." "We chose to say nothing at the time." "He chose badly and regretted it."
The test that settles it
Add a time word to the front of the sentence. If yesterday or last year fits comfortably, you want chose. If today, usually or tomorrow fits, you want choose.
A second, faster check: look for a helping verb. After will, would, can, could, should, must, might, do, does, did, to and have to, the verb never changes form — so it is always choose. "Did you choose?" not "Did you chose?" This is the single most common mistake with this pair, and the helper rule catches all of it.
The memory trick
Choose has two o's and is the longer word — use it for the longer-lasting present and future. Chose is shorter, like the past that is already over and done. Or lean on the rhymes: choose/news is what is happening now; chose/nose is what happened before.
The third form
Once you add have, has, had or a form of be, neither spelling is right — you need chosen. "I have chosen." "She was chosen for the team." "They had chosen already." Writing "I have chose" is common in casual speech in some varieties of English, but it is treated as an error in writing of any formality.
A pronunciation note
Because the vowel sound genuinely differs, reading a sentence aloud usually exposes the mistake even when the eye misses it. "Yesterday I chooze the fish" sounds wrong immediately.
Watch the -s form
With he, she or it in the present, add an s to the present stem: chooses. "He chooses the music." There is no such form as "choses", and the past never takes an s: "he chose the music" is already complete.
Frequently Asked Questions
Is it "did you choose" or "did you chose"?
"Did you choose." The word did already carries the past tense, so the main verb stays in its base form. The same applies to didn't: "I didn't choose that."
Is "I have chose" ever correct?
No. After have, has or had you need chosen: "I have chosen." You will hear "I have chose" in some spoken dialects, but it is not accepted in standard written English.
How do I remember which one rhymes with what?
Choose rhymes with news, and news is happening now. Chose rhymes with nose, and it is the past. Reading the sentence aloud is usually enough to catch a slip.