Difference between small and big letters in japanese
Hello. Uuh, in hiragana/katakana I sometimes see normal letters and small letters together like the letter Te(テ) and a small i(イ)..

What is the difference between テイ and ティ?(random letters,, I dont know if it actually means something)

Question

Difference between small and big letters in japanese
Hello. Uuh, in hiragana/katakana I sometimes see normal letters and small letters together like the letter Te(テ) and a small i(イ)..

What is the difference between テイ and ティ?(random letters,, I dont know if it actually means something)

Answer

When you see small letter of Japanese alphabet, small one go together with the big or normal letter which is right before small letter. Let's take your example. pronunciation of  テイ is TEI and pronunciation of ティ is TI.

Answer

It is difference of Japanese pronunciations.
テイ is two pronunciations, テ and イ, but ティ is one pronunciation in 2 letters.
For example, pronunciation of "tail" is テイル. This pronunciation resembles テイ.
pronunciation of "tea" is ティー. This pronunciation resembles ティ.
So, ティ is one of anomalistical Japanese pronunciations.