Why in words like temperate there is a small ə in it?
I'm looking at the version in the Cambridge English Dictionary
English Language Learners Stack Exchange is a question and answer site for speakers of other languages learning English. It only takes a minute to sign up.Sign up to join this community
That superscript schwa means that the R is syllabic for some speakers i.e. capable of making a syllable of its own. You will also hear it being pronounced with the schwa. For syllabic consonants, we use another diacritic (a small vertical line below the consonant) in phonetic transcriptions, but dictionaries use [ᵊ] before the syllabic consonants for convenience. You could transcribe temperate alternatively as [ˈtem.pɹ̩.ət]. Note that I used [ɹ] because [r] is the symbol for a trilled R (again, IPA uses /r/ for convenience).
Similarly, button is /ˈbʌtᵊn/ (syllabic n or /-ən/), bottle /ˈbɒtᵊl/ (syllabic l /-əl/).
The small schwa is not used by all dictionaries. For example, you can check the word in the Oxford dictionary and find it written /ˈtempərət/.
IPA has its own spelling rules and conventions. The Oxford & Cambridge dictionaries do not follow the same conventions; this reflects a lack of standardisation.
Both transcriptions of 'temperate' have the same pronunciation: /ˈtem.pᵊr.ət/ & /ˈtempərət/
As a side note, there is a variant of 'temperate' that is pronounced as two syllables. It can be written in IPA in different ways, according to different styles of transcription:
Some of the above examples are more difficult to read / understand than others. If the transcription needs to be explained every time, then it is overly complex and therefore unhelpful to most English learners.