So in first learning the IPA I went through the consonants and the vowels. This is confusing because in the consonants chart you see stuff like [d̪] or [ʎ̥˔]. At first I thought these were just some extra consonants. But then I saw in some different phonologies such as this, symbols like [pʰ] or even [ɡ̊eːˀ].
Then I ran into the X-SAMPA diacritics, which helped explain what was going on.
_" ̈ centralized _+ ̟ advanced _- ̠ retracted _/ ̌ rising tone _0 ̥ voiceless _< implosive (IPA uses separate symbols for implosives) = ̩ syllabic _> ʼ ejective _?\ ˤ pharyngealized _\ ̂ falling tone _^ ̯ non-syllabic _} ̚ no audible release ` ˞ rhotacization in vowels, retroflexion in consonants (IPA uses separate symbols for consonants, see t` for an example) ~ ̃ nasalization _A ̘ advanced tongue root _a ̺ apical _B ̏ extra low tone _B_L ᷅ low rising tone _c ̜ less rounded _d ̪ dental _e ̴ velarized or pharyngealized; also see 5 <F> ↘ global fall _F ̂ falling tone _G ˠ velarized _H ́ high tone _H_T ᷄ high rising tone _h ʰ aspirated _j ʲ palatalized _k ̰ creaky voice _L ̀ low tone _l ˡ lateral release _M ̄ mid tone _m ̻ laminal _N ̼ linguolabial _n ⁿ nasal release _O ̹ more rounded _o ̞ lowered _q ̙ retracted tongue root <R> ↗ global rise _R ̌ rising tone _R_F ᷈ rising falling tone _r ̝ raised _T ̋ extra high tone _t ̤ breathy voice _v ̬ voiced _w ʷ labialized _X ̆ extra-short _x ̽ mid-centralized
I have seen some of those other ones around like [ˠ], [ ̪], [ ̟], [ˤ], and [ʷ], but I haven't seen many of the others.
I am wondering (a) where I can learn about each of these symbols in more depth (perhaps some encyclopedia about IPA diacritics, Wikipedia only has links to some of them), and (b), if these are somewhat repetitive in certain cases. That is, it seems that, for example, [ɱ] is a labiodental thing, but you could also do [m̪]. Same with "velarized" things (ˠ), it seems to me those are already covered by the velar consonants like [ŋ] or the similar looking [ɣ]. For example, doesn't seem like you'd ever do [ɣˠ], but here you see [bˠ], even [ɾˠ]. (Interested to learn what all these symbols mean). Same for pharyngealized (ˤ), implosive (IPA uses separate symbols for this), etc. Some pharyngealized ones are found here or here, such as [dˤ] or [ðˤ]. Labialization is found here, such as [gʷ], not sure what that means (hoping some aggregated resource has all this somewhere). For the voiceless stuff ( ̥), the IPA had a few consonants listed in the chart, such as [ʎ̥˔], so seems a bit duplicated (not sure if the meaning is the same). In addition, they already have symbols for a whole range of voiceless consonants (ɸ, f, θ, s, etc.), so seems like duplication as well. Wondering if these "super/subscripts" like [ˠ] or [ ̥] are used for some specific purpose that is required outside of these voiceless/velarized/etc. symbols in the consonant chart. Perhaps it was a later invention. The rest of these symbols I haven't really seen, so not sure what their status or use is.
So basically just wondering where I can learn about all of these things, and if this duplication I am pointing out is real or I am missing something.