Pronunciation and speaking: hesitating
Lower intermediate to advanced level English (B1-C1) 

Speaking continuously is quite difficult, even for native speakers. Almost all speakers of English need to pause frequently. Hesitating gives you more time to think and choose the right words.
In standard British English it is common to use the sounds ‘er’ or ‘um’ while you are hesitating. This is quite normal and is usually better than being completely silent. If you don’t make a noise at all, the listener might become a bit uncomfortable.

Here’s an example of typical hesitation.

Pete: What are you doing tonight? Got any plans?
Pat: Well, er, I might, um, see a few friends and then, er, get an early night.

‘er‘ is the sound in ‘her’ and ‘um‘ is the sound in ‘mum’

It’s important to realise that people hesitate differently in different languages and it can be a key way to help you sound more natural. Think about how you hesitate in your language and listen for how people do it in English (listening to the radio is a good way to do this).

If you feel strange hesitating in a British way, you could imagine you are an English actor!