Here is the rule, stated plainly: a small group of very common English words has two pronunciations, and the one you use depends on the grammatical job the word is doing in the sentence. The words that, some, as, there, one and any each have a strong form with a full vowel and a weak form with a reduced vowel, usually the schwa /ə/.
The principle behind all of it is one sentence: function words reduce, content words keep their full vowel. Nouns, main verbs, adjectives and adverbs carry meaning, so they keep their vowels. Pronouns, articles, prepositions, conjunctions and auxiliaries are grammatical glue, so they get squeezed. A function word only takes its strong form when it is stressed, contrasted, or sitting at the end of a phrase. Learn that one sentence and the rest of this article is just examples.
"That": The Fastest Test in English
The word that is the clearest case, and it comes with a test you can run in half a second.
When that is a demonstrative, meaning you are pointing at something, it is strong: /ðæt/. It carries meaning, it can be stressed, and you could replace it with this.
- I like that one. /aɪ laɪk ðæt wʌn/
- That is not what I said.
- Who told you that?
When that is a conjunction or a relative pronoun, it is weak: /ðət/. It carries no meaning at all, it is pure grammar.
- I think that it works. /aɪ θɪŋk ðət ɪt wɜrks/
- The book that I bought. /ðə bʊk ðət aɪ bɑt/
- She said that she would come.
The delete test
If you can delete the word "that" and the sentence still works, it is weak. "I think it works" is fine, so that that is weak /ðət/. "I like one" is not the same sentence, so that that is strong /ðæt/. This test is nearly perfect and it costs you nothing to run while you speak.
"Some": Vague Quantity vs Contrast
When some means an unspecified, unimportant amount, it is weak: /səm/. This is the everyday use, and it is by far the most common one.
- I need some water. /aɪ nid səm ˈwɔɾər/
- Can I have some help?
- We bought some bread.
When some means "some, as opposed to others", it is strong: /sʌm/. The contrast is the whole point of the sentence, so the word gets a full vowel and stress.
- Some people like it, others do not.
- Some of us disagree.
"As": Almost Always Weak
As is weak /əz/ in nearly every sentence you will ever say. The classic case is the as ... as comparison, where both instances reduce and glue onto the words around them.
- as soon as possible /əzˈsunəz ˈpɑsəbəl/
- as fast as you can /əz fæst əz ju kæn/
- He works as a teacher. /hi wɜrks əz ə ˈtiːtʃər/
The strong form /æz/ shows up only when as is stranded at the end of a phrase or deliberately emphasized, which is rare.
"There": Existential vs Place
This pair trips up almost everyone, because the two theres look identical on the page.
Existential "there" is the dummy subject in "there is", "there are", "there was". It points at nothing and means nothing, so it is weak: /ðər/.
- There's a problem. /ðərz ə ˈprɑbləm/
- There are three options. /ðər ər θri ˈɑpʃənz/
Place "there" is an adverb of location. It points at a real spot in the world, so it is strong: /ðɛr/.
- Put it there. /pʊt ɪt ðɛr/
- I went there last year.
"One" and "Any"
One as a number is strong: /wʌn/. "I only have one." As a pronoun standing in for a noun, it reduces to /wən/: "the red one", "which one?", "the ones I bought".
Any follows the same logic. In a neutral question or negative it reduces toward /ˈɛni/ with a very light first syllable: "Do you have any questions?" When it means "any at all, no restriction", it takes full stress: "Pick any card you want."
Strong and Weak Forms at a Glance
| Word | Weak form | When weak | Strong form | When strong |
|---|---|---|---|---|
| that | /ðət/ | conjunction, relative pronoun | /ðæt/ | demonstrative (pointing) |
| some | /səm/ | vague quantity | /sʌm/ | contrast: some, not others |
| as | /əz/ | comparison, "in the role of" | /æz/ | stranded or emphasized |
| there | /ðər/ | existential subject | /ðɛr/ | place adverb |
| one | /wən/ | pronoun: the red one | /wʌn/ | the number |
| at | /ət/ | normal preposition | /æt/ | end of phrase: looking at? |
| of | /əv/ | normal preposition | /ʌv/ | end of phrase: made of? |
The End-of-Phrase Rule
This is the part learners most often miss. A function word that would normally reduce goes back to its strong form when it lands at the end of a phrase, because English does not like to end a group of words on a weak beat.
- What are you looking at? Strong /æt/, not /ət/.
- Where are you from? Strong /frʌm/.
- Who is it for? Strong /fɔr/.
- But: I'm looking at the sky. Weak /ət/.
Practice Words
Practice: Sentence Pairs
Say each pair out loud, back to back. The contrast is what trains your ear. Exaggerate at first; the difference will settle into something natural on its own.
- I like that /ðæt/ car. / I know that /ðət/ you left.
- That /ðæt/ was expensive. / The one that /ðət/ was expensive.
- Some /sʌm/ agree, some do not. / I want some /səm/ coffee.
- There /ðɛr/ it is. / There's /ðərz/ one left.
- Give me one /wʌn/. / Give me the blue one /wən/.
- Come as /əz/ soon as /əz/ you can. / Do it exactly as /æz/ shown.
- What are you looking at /æt/? / I'm looking at /ət/ the menu.
Once this clicks, the same logic will explain a lot of what you hear in fast speech. Next, look at how English also drops whole syllables inside single words in our guide to schwa deletion in every, family and chocolate, and at how the word "and" collapses to /ən/ in connected speech. You can drill these patterns in full sentences with our sentence pronunciation practice.