Two small prefixes appear in hundreds of everyday English words: inter- (international, internet, interview) and trans- (transition, translate, transport). Both follow simple logic in American English. In inter-, the /t/ after the n usually fades, so internet sounds like "INNER-net" and international like "inner-NASH-uh-nul". In trans-, the last sound of the prefix is /s/ or /z/ depending on what comes next: transport keeps /s/, but transition usually has /z/.
Why does this matter? These are core words of work, travel, technology and study. If you pronounce every letter of inter- and stress the wrong syllable ("in-ter-NET"), or stress the noun transport like the verb, listeners need an extra moment to understand you. Learn the two patterns once and you can handle dozens of words, including ones you have never heard. One honest note first: these are strong tendencies, not laws. American speakers vary on several words, and either version is understood.
The Rule in Short
- inter- = /ɪnɚ/: the /t/ between n and the weak /ɚ/ is usually dropped or reduced to a very quick tap, so inter- sounds like inner. Careful speech and British English often keep a light /t/.
- Short nouns stress inter- on the first syllable: INternet, INterview, INterval, INterface, INterstate.
- Verbs (and most adjectives) put the main stress later and keep a secondary stress on inter-: interACT, interRUPT, interFERE, interMEdiate, interNAtional.
- trans- before a vowel or a voiced consonant tends to end in /z/: transition, transistor, transit, translate, transmit, transatlantic.
- trans- before a voiceless consonant keeps /s/: transport, transfer, transform, transcript, transparent, transplant.
- Verbs with trans- stress the stem: transFER, transLATE, transFORM. In noun-verb pairs the noun moves the stress forward: the noun TRANSport, the verb transPORT.
Why It Works
The weak t in inter-
In American English, a /t/ that sits between /n/ and an unstressed vowel is often dropped or flapped. It is the same process that makes winter sound like "winner" and twenty like "twenny" (see our guide to the medial t after n). The syllable -ter in inter- is exactly that environment: stressed or half-stressed in, then a weak ter. So interview is "INNER-view", and internet and international even merge two n sounds into one slightly longer n: "INNER-net", "inner-NASH-uh-nul". The vowel in ter becomes the r-colored schwa /ɚ/, with no separate "e" and no separate trilled "r".
Why nouns stress inter- and verbs do not
English likes to put stress at the front of nouns and at the back of verbs (REcord the noun, reCORD the verb; see noun-verb stress shift). Words with inter- follow that habit. Short, concrete nouns have the main stress on inter-: INternet, INterview, INterval, INterface. Verbs keep the stem strong and give the prefix only a secondary stress: ˌinterˈACT, ˌinterˈRUPT, ˌinterˈFERE. Longer words are controlled by their suffix: -al pulls the main stress to interNAtional, -tion to interSECtion and interACtion. In every case the first syllable keeps at least a secondary stress, so say a clear /ɪ/ there, not a schwa.
Why trans- changes between s and z
The prefix trans- ends in /s/, and English prefers a smooth voicing flow. After /n/ and before a vowel or a voiced consonant (l, m, d, g, v), your vocal folds are already vibrating, so the /s/ tends to become /z/: tran-ZISH-un, tranz-LATE. Before a voiceless consonant (p, t, k, f, s) the folds switch off, so the /s/ stays: TRANS-port, trans-FORM. This is the same kind of adjustment you hear in the prefix dis- (see dis- as s or z) and in intervocalic s voicing. The difference is that trans- is a tendency, not a rule: for transition, transit, translate and transmit, dictionaries list both /s/ and /z/, and both are heard.
Why trans- verbs stress the stem
Trans- means "across", and in verbs it works like a light prefix: the meaning sits in the stem, so the stem takes the stress. Transfer (verb) is trans-FUR, translate is trans-LATE, transform is trans-FORM. When English has a noun and a verb with the same spelling, the noun usually shifts the stress to the front: a TRANSport versus to transPORT, a TRANSfer versus to transFER, a TRANSplant versus to transPLANT.
Pattern Tables
Read each word aloud, mark the stress, and check whether the t fades (inter-) or the s becomes z (trans-). Where two versions are common, the first one is the safer choice.
Words with inter-
| Word | IPA (US) | Respelling | Pattern |
|---|---|---|---|
| internet | /ˈɪnɚˌnɛt/ | INNER-net | noun, stress on inter-; t fades |
| interview | /ˈɪnɚˌvju/ | INNER-vyoo | noun and verb, stress on inter-; t fades |
| interval | /ˈɪnɚvəl/ | INNER-vul | noun, stress on inter- |
| interface | /ˈɪnɚˌfeɪs/ | INNER-fayss | noun, stress on inter- |
| interstate | /ˈɪnɚˌsteɪt/ | INNER-state | noun or adjective, stress on inter- |
| interact | /ˌɪnɚˈækt/ | inner-ACT | verb, stress on the stem |
| interrupt | /ˌɪnɚˈrʌpt/ | inner-RUPT | verb, stress on the stem |
| interfere | /ˌɪnɚˈfɪr/ | inner-FEER | verb, stress on the stem |
| intermediate | /ˌɪnɚˈmidiət/ | inner-MEE-dee-it | adjective; stress moves later |
| international | /ˌɪnɚˈnæʃənəl/ | inner-NASH-uh-nul | adjective; suffix -al sets the stress |
| interesting | /ˈɪntrəstɪŋ/ | IN-truh-sting | not a prefix word; usually 3 syllables (careful: /ˈɪntərɛstɪŋ/) |
| internal | /ɪnˈtɝnəl/ | in-TURN-ul | not the prefix; t stays, stress on ter |
| interior | /ɪnˈtɪriɚ/ | in-TEER-ee-er | not the prefix; t stays, stress on ter |
| interpret | /ɪnˈtɝprət/ | in-TUR-prit | not the prefix; t stays, stress on ter |
Words with trans-
| Word | IPA (US) | Respelling | Pattern |
|---|---|---|---|
| transition | /trænˈzɪʃən/ | tran-ZISH-un | z before a vowel (also /trænˈsɪʃən/) |
| transistor | /trænˈzɪstɚ/ | tran-ZISS-ter | z before a vowel (also /trænˈsɪstɚ/) |
| transit | /ˈtrænzɪt/ | TRAN-zit | z before a vowel (also /ˈtrænsɪt/); stress first |
| transatlantic | /ˌtrænzətˈlæntɪk/ | tranz-at-LAN-tik | z before a vowel (also /ˌtrænsət-/) |
| translate | /trænzˈleɪt/ | tranz-LATE | z before voiced l (also /trænsˈleɪt/) |
| transmit | /trænzˈmɪt/ | tranz-MIT | z before voiced m (also /trænsˈmɪt/) |
| transaction | /trænˈzækʃən/ | tran-ZAK-shun | z before a vowel (also /trænˈsækʃən/) |
| transport (n.) | /ˈtrænspɔrt/ | TRANS-port | noun /ˈtrænspɔrt/; verb /trænˈspɔrt/ |
| transfer (v.) | /trænsˈfɝ/ | trans-FUR | verb; noun is /ˈtrænsfɝ/ |
| transform | /trænsˈfɔrm/ | trans-FORM | s before voiceless f |
| transcript | /ˈtrænskrɪpt/ | TRAN-skript | s before voiceless k; stress first |
| transparent | /trænˈspɛrənt/ | tran-SPAIR-unt | s before voiceless p |
| transplant (v.) | /trænsˈplænt/ | trans-PLANT | verb; noun is /ˈtrænsplænt/ |
| transcend | /trænˈsɛnd/ | tran-SEND | double s becomes one s sound |
Exceptions and Variation
- interest is not really a prefix word. It is usually /ˈɪntrəst/ and interesting /ˈɪntrəstɪŋ/, only three syllables (IN-truh-sting). The four-syllable /ˈɪntərɛstɪŋ/ is fine in careful speech, but "in-te-RES-ting" is not English stress.
- internal, interior, interpret, interrogate, intern start with in- plus a stem that begins with ter. The t belongs to a stressed or half-stressed syllable, so it stays: in-TURN-ul, in-TEER-ee-er, in-TUR-prit.
- Words with suffixes follow the suffix: intersection, interaction, intermission have main stress just before -tion, even though they are nouns.
- interview is INterview as a noun and as a verb. Do not move the stress for the verb.
- Careful and British speech often keep a light /t/ in inter- (/ˌɪntəˈnæʃnəl/). Both are understood; in fast American speech, the dropped version is the one you will hear.
- translate has the most variants: /trænzˈleɪt/, /trænsˈleɪt/, and some Americans even stress the first syllable. transient can be /ˈtrænʃənt/ or /ˈtrænziənt/.
- transport as a noun is common in British English ("public transport"); Americans more often say transportation /ˌtrænspɚˈteɪʃən/ and use transport mostly as a verb or in technical contexts.
- transcend and transcribe: trans- followed by s (or sk) gives one long s sound, not two: /trænˈsɛnd/, /trænˈskraɪb/.
Common Learner Mistakes
- Stressing the last syllable of internet ("in-ter-NET"), as many languages do. In English the noun is INNER-net, with a weak second half.
- Pronouncing a full, hard t in inter- ("IN-ter-view" with a strong t). It is not wrong, but it sounds slow and formal; "INNER-view" sounds natural.
- Adding a trilled or tapped r in inter-. Use one smooth r-colored vowel /ɚ/.
- Swallowing the s in trans- before consonants ("tran-port", "tran-fer"). Keep the /s/: trans-port.
- Saying -tion as /sjon/ in transition and transaction. The ending is /ʃən/: tran-ZISH-un.
- Using the same stress for noun and verb: "I will TRANSfer the money" or "a transFER form". Verb: transFER. Noun: TRANSfer.
- Worrying too much about s versus z. Saying /trænsˈleɪt/ for translate is perfectly acceptable. Stress and the /æ/ vowel matter more.
How to Practice
- Start from winter. Say winter, inner, inter, then internet, interview, international. Notice how inter and inner can sound alike.
- Slow to fast. Say "in-ter-net", then "in-ner-net", then "innernet" at normal speed. Do the same with international.
- Clap the stress. Clap harder on IN for internet and on ACT for interact. Switch between the two.
- Throat test. Put two fingers on your throat. Say transport: no buzz at the s. Say transition: you should feel a buzz before the next vowel.
- Noun-verb drill. Say "a TRANSfer, to transFER", "a TRANSport, to transPORT", "a TRANSplant, to transPLANT". Make the contrast clear.
- Record yourself reading the practice sentences below and compare with the audio on the practice cards.
Practice
Practice Sentences
- The international interview was an interesting experience.
- Please don't interrupt the intermediate class.
- The internet company handled the transition smoothly.
- I need to transfer to another bus, but public transportation is cheap.
- Can you translate this transcript for me?
- The glass is transparent, so we can see the transit station.
- The interstate was busy, so the interviewer arrived late.
- The new transistor will transform how we interact online.
Quick Summary
- inter- = INNER: the t after n usually fades. Say a clear /ɪ/ and one smooth /ɚ/.
- Short nouns stress inter- (INternet, INterview); verbs stress the stem (interACT, interRUPT); suffixes decide the rest (interNAtional).
- interest(ing) is not a prefix word: IN-truh-sting, three syllables.
- trans- before vowels and voiced sounds tends to /z/ (transition, translate, transit); before voiceless sounds it is /s/ (transport, transfer, transparent).
- Americans vary on several trans- words; either version is understood.
- Verbs stress the stem (transFER); matching nouns stress the front (TRANSfer, TRANSport).