There are various reasons behind why we hesitate to talk

Hesitation is an unwillingness to do something, or a delay in doing it, because you are worried, or embarrassed about it. Hesitation happens when you feel uncertainty or doubt. It can be a pause in speech, a faltering moment before you act, or a silent second of indecision.

Hesitation is internal. Each person functions according to their particular nature. Although this nature is not evident in the normal behaviour or character, it can be perceived in a different way and educated to be receptive and true to the aim or direction that you have set for yourself in life. It is reflected in every kind of thinking, behaviour, attitude and performance.

There are various reasons behind why we hesitate to talk:

Lack of content: they basically don't know what to talk about, they lack knowledge, they lack content about various topics.

Unable to express: there is a problem with some people who actually know a lot but are poor in expressing themselves because they lack the communication skills required.

Lack of confidence: this is the biggest and the most important point in life, if you are under confident about something then you are never going to make it through.

Poor communication skill: people who have weak vocabulary and poor grammar also hesitate of being corrected by someone superior so they hesitate to talk.

Inferiority complex: underestimating yourself, your skills ,your knowledge when put infront of a group of people.

Problem is that we tend to think a lot before we talk. Inferiority complex.