Hallo everyone 
My name’s Iwona and I’m new in Audacity. I’m not english native speaker, so sorry for my mistakes.
This is my question:
Is it possible to automatically extend the pause between words in the recording. I have a lot of individual words (1000) in one record and I want to the pause will be longer between each other.
No. Audacity does not recognize languages, so it doesn’t know about spaces between words.
Koz
I guess what you want is like the opposite of the Truncate Silence effect?
Unfortunately Audacity does not have an effect to do this, and even if Audacity could it would not work well for detecting words as the gaps between words in normal speech are not distinct.
Although the process cannot be automated, to speed up the job of manually inserting silence, generate a bit of silence and copy it (select the required amount of silence and press Ctrl+C). To insert the silence between words, click on the track between two words and press Ctrl+V to paste the silence.
It is possible to lengthen the silence between words or phrases with a plug-in called “silencelength.ny”. This works on a Mac, but I don’t know if it will work on a PC.
I found this plug-in somewhere on the internet several years ago and used it successfully with Audacity 1.3.
Later when I upgraded to Audacity 2.02 the option to lengthen silences had gone, but I managed to solve it by copying the file called “silencelength.ny” from my old folder called audacity ver 1_3/plug-ins to the folder called Audacity ver 2_0_2/plug-ins. The audacity program folder should be in your applications folder.
I think you can find the plug-in here, but I can’t guarantee its the same one I found:
https://forum.audacityteam.org/t/lengthen-silences/12326/1
There seems to be a bug in my version. It wont work with Stereo tracks so first you need to convert the track to mono by clicking Tracks - Stero Track to Mono.
To launch the plug in, re-start audacity (from your applications folder) and then open any MONO track (or convert a stereo one to mono) and then click ==> Effect==>Silence Lengthen. You then choose what audio level constitutes “silence” (the default of 26db works fine), and the minimum duration which constitutes a silence (default is 0.3s of silence), and then set the number of secondes to insert. For learning languages, I insert 2.5 seconds.
I see that it has come back to haunt me 
I’ll have a look and see if I can make it a bit more elegant (and fix the bug) 
Although the process cannot be automated, to speed up the job of manually inserting silence, generate a bit of silence and copy it (select the required amount of silence and press Ctrl+C). To insert the silence between words, click on the track between two words and press Ctrl+V to paste the silence.
Thank you for this suggestion. I selected the silence at the end of the file and pasted it between words within the file. (But I have much less than 1000 words. . . . )