Why is the initial “ts” sound (e.g “tsunami”) pronounced as “s”?

Question

Why is the word "tsunami" often pronounced as "sunami"? Can English speakers pronounce "ts"? Is it because the initial "ts" looks foreign?

Answer 1

English speakers, like all speakers on the planet without speech impediments, can in principle pronounce any sound used by any other language.

However, it isn't part of the normal phonotactics of English for the combiantion /ts/ to occur in syllable-initial position. There's therefore a tendency to adapt the pronunciation to fit in with the combinations of sounds generally found in native English words, as with other words and with loanwords in other languages. There's also a tendency in English, and indeed in other languages, to simplify consonant clusters generally in pronunciation.

It can work the other way round: an influx of loanwords can in principle lead to an "alien" sound or combinations of sounds being adopted in a language. But for this to happen probably requires a reasonable number of loanwords with the given sound/combination.

Answer 2

The "ts" sound is called Voiceless alveolar affricate and it is a feature of some languages, but not English.
There are some borrowed foreign words that include it in the original language-see below.
In English, the affricate is pronounced:

• by adjoining a "t" and a "s" (e.g. piazza, pizza, pizzicato), similar with catsup.
• by an approximation of the original sound (e.g. tsunami, tsetse, tsar,blitz). I don't know how close is to the original sound, but certainly there can be differences. For example, the sound might be dental in the original language, and alveolar in English.
• or "t" is eliminated, so you are left with s (tsunami) or z (tsar).
• or "s" is eliminated (tsetse).

You will hear "tsunami" with a "ts" more often than without it. See Forvo for examples.

As a side note, I was wondering why "plaza" is not pronounced with the English equivalent of "ts". It turns out that the word comes from Spanish, not Italian, and Spanish (Castilian) does not have that sound.

Sources consulted:
1. Cambridge English Pronouncing Dictionary.
2. A practical introduction to phonetics, J.C.Catford.

Answer 3

My local dictionary offers these two pronunciations for tsunami: |tsoōˈnämē| and |soōˈnämē|. The ts sound is primary used in loan words and is extremely uncommon. English speakers will typically drop the t from tsunami. Here are a few other words with beginning ts all found in my dictionary:

• czar/_tsar_ — |zär; (t)sär|
• tsatske — a variant of tchotchke; my dictionary only had a pronunciation as |ˈ CH ä CH kə| which seems to refer to the tch spelling
• tsetse — |ˈ(t)sētsē; ˈ(t)set-|
• tsk — typically pronounced |tisk| but the associated sound drops the i sound
• tsuba — |ˈtsoōbə| Note that the t here is not considered optional

Answer 4

Your intuition is correct. Tsunami is a borrow word from Japanese, where the word is "harbor wave", roughly pronounced Tsunami. However, in English, we don't have the 'tsu' sound (Americans can't say the sound well), so we just go with 's' instead.