Learn English – Do they notice me if I use /d/ instead of ‘th’ sound

Consonant clusters like this are not all that comfortable for native English speakers either. Carefully pronouncing all the consonants is more work than it's worth, and actually sounds unnatural. Usually there is some degree of elision. Each speaker evolves a personal, 'idiolectal' approach; but there are a couple of general tendencies which make these word-final clusters easier.

• The final consonant is 'carried over' to head the following syllable if this results in an acceptable syllable head. In your example, for instance, the collocation tufts out is read as if it were tuft sout. The cluster /st/ is a frequent syllable head, so the word Borstal is spoken Bor stal. Occasionally this will involve eliding the beginning of the following syllable: tufts had, for instance, would be spoken as tuft sad.

• Stops (/p/, /b/, /t/, /d/, /k/, /g/) which close a syllable or occur before a consonant are not aspirated, and if a following consonant has the same point of articulation they virtually disappear. In your example, /t/ and /s/ have the same point of articulation, and the /t/ is discernible only as a slight sharpening of the attack on the /s/ -- which, as said, heads the following syllable. There's not even a complete closure of the airflow, only a slightly marked narrowing: /tuf-sout/. (I have no idea how the IPA represents this.) This will be true at the end of a sentence, too, where there's no carryover: He pulled his hair out in tufts .. /tuf-s/

The most useful thing to keep in mind is that people don't speak in words but 'utterances', and they will redistribute the word boundaries to suit established oral patterns.

/i:/ is the vowel that we find in the word FLEECE. I put that word in capitals because that is how that vowel is often referred to by linguists: the fleece vowel - or FLEECE for short. (This is not random, the word was specifically chosen for a number of specific reasons.) It is the vowel sound at the end of the word guarantee. In transcriptions of British English it has a colon [ : ] in the symbol to describe the length.

/ɪ/ is the vowel in the word KIT. It is known as the kit vowel - or KIT for short. It is the vowel we find in prefixes and suffixes, the bits we stick onto the beginnings and ends of words. So, for example it is the vowel we hear in --ing verb endings.

The vowel represented by /i/ at the ends of words in dictionaries is usually referred to as the happy vowel - HAPPY. This vowel may sound like either FLEECE or KIT, but is always short in duration.

If you say the < y > sound that we find in the word yes, and then say the < e> we find in the word end, the kit vowel is somewhere between the two sounds. This is the first vowel in the word infinitely. This word would sound very odd to a native speaker if it was said with a fleece vowel, /i:/! It would sound like a made-up word: eenfinitely.

The Original Poster asks if there is a big difference between these vowels. If we are talking about the physical difference between the sounds, the answer is: no. In fact, it is very unusual to have two vowels that are so similar in one language. They are very close together. In most languages these would count as one vowel. However, if we are talking about the meaning, or the effect on a listener, the answer is: yes! There is a big difference. There are very, very, very many words that we can be confused about if you say the wrong vowel. For example, the words peace and piss. Nobody wants to say Piss man!, when they mean Peace man!.

If you want to type IPA script, this website is very useful

Hope this helps,

Peace!