Pronunciation: [tˈʌt͡ʃ ˌʌp ˈɒn] (IPA) 
The correct spelling of the phrase "touch up on" is actually "touch upon". The word "upon" is pronounced with the sound /əˈpɒn/, as opposed to the incorrect spelling of "up on" which would be pronounced with /ˈʌp ɒn/. The phrase "touch upon" means to briefly mention or discuss a topic. It is important to use correct spelling and pronunciation in order to effectively communicate with others.
The phrase "touch up on" is an idiomatic expression that typically means to review or refresh one's knowledge, skills, or understanding of a particular subject or topic. It implies the act of revisiting or going over the basics or finer details of a subject in order to enhance or improve one's understanding or abilities.
When someone mentions that they need to "touch up on" something, they are expressing a desire or intention to go back and remind themselves of certain details or concepts in order to keep their knowledge current or to sharpen their skills. This phrase is often used in educational or professional contexts, where individuals may feel the need to brush up on their knowledge to perform better in an upcoming exam, presentation, or task.
"Touching up on" a topic can involve various methods, such as reading educational materials, revisiting lecture notes or textbooks, watching informative videos, or engaging in discussions with peers or experts. It allows individuals to reinforce their understanding, fill in any gaps in their knowledge, and stay updated in a rapidly evolving field.
In summary, "touching up on" refers to the act of refreshing or reviewing one's knowledge or skills in order to improve understanding and performance. It denotes a conscious effort to revisit a subject or topic to ensure competence and mastery.
