A constanant is a letter that is not a vowel. Vowels: a,e,i,o,u and somtimes y
Isn’t a vowel aeiou all other letters are then constanants
there is no letter t in Japanese, as the Japanese alphabet is phonetic so every constanent has a vowel sound attached i.e. タチツテト in katagana is ta,chi,tsu,te,to. they are the T sounds of the katagana alphabet. there are 2 other alphabets. hiragana and kanji
in kanji the letters represent meanings and sounds not just sounds alone in hiragana and katagana the letters only represent sounds similar to English however the individual letters represent a vowel or a constanent/ vowel combination with the exception of n an example both haragana and katagana written in roman letters look like the following a i u e o ka ki ku ke ko ga gi gu ge go sa shi su se so za ji zu ze zo ta chi tsu te to da di du de do na ni nu ne no ha hi fu he ho ba bi bu be bo pa pi pu pe po ma mi mu me mo ya yu yo ra ri ru re ro WA wo n