Be wary of pedagogical approaches to woodwind articulation that depend on analogies to speech sounds.
The most common, at least in the English-speaking world, is the idea that tonguing is like saying “too” or “doo.” And certainly there are significant mechanical similarities, especially with “too.” “Doo” doesn’t work as well because it is a voiced consonant, produced essentially the same way as “too” but with vibration of the vocal cords, an undesirable effect for woodwind playing (except for some extended techniques).
Some teachers recommend something like “too” for crisper articulations and “doo” for gentler ones. If you compare carefully your whispered (unvoiced) “t” and “d” sounds, you may find that they are not, in fact, completely identical. My “t” gives a bit more explosive sound, because I release the entire tongue, and my “d” is softer because I tend to release only the tip of the tongue, keeping the back in contact with my molars. But this difference doesn’t apply to good woodwind playing technique, in which the back of the tongue must be kept independent from the tip in order to manipulate voicing.
“Loo” is another one that gets mentioned sometimes for gentler articulations. This one also doesn’t work well if taken literally because (1) the “l” sound is voiced and (2) it leaks air around the sides of the tongue. (You can approximate an unvoiced version by whispering “lll…,” but that sound isn’t typically used in English.) A woodwind book I read recently recommends some additional oddities like “droo” or “thoo.” “Droo” doesn’t work well because it has a sequence of two consonant tongue positions, one of which is voiced. “Thoo” (presumably the unvoiced version) leaks air near the tip of the tongue.
Another point worth making is that consonant sounds in English aren’t necessarily the same as consonants in other languages, so even if we select some workable English consonant sounds, it’s not a given that those are the ideal choices. (Plenty of study has already been done on this topic.)
And that’s just the consonants. Assuming they are used as a shorthand for describing articulations, with an understanding that they do not precisely represent articulation technique, vowel sounds can still cause confusion. Consider the “oo” in “too.” Vowel sounds are loosely analogous to woodwind voicings, so it is best to match the vowels to the instrument. Is “oo” the right voicing to evoke?
For low-voiced instruments, an “oh”- or “ah”-like vowel sound is a better match. (“Oh” is still problematic because English speakers pronounce it as a diphthong, two vowel sounds in sequence—this will cause unstable pitch and tone when applied to a woodwind instrument. To avoid this, we must borrow an “o” sound from another language.) For the clarinet, “ee” is the closest match. For saxophones, the vowel sound needs to be somewhere in between, perhaps near the schwa (ə) sound like the “a” in “about.”
Language sounds can be used only as a very limited analogy for woodwind articulation technique—use them with care.