As for your first question: Well, that depends on how specifically you want it. If you want to do it real-time, i.e. you want proper words to appear as you type random stuff, well, good luck with that. If you have a text with random letters, you could afterwards look for proper anagrams of every word in the text. You will require a list of proper words to see if they are anagrams, however.
Note that also "a sentence with proper words" is a completely different thing than "a proper sentence". The former is done relatively easy with enough time and effort, while the latter is (close to) impossible to do, as you require your program to have knowledge of both grammar and the type of words (i.e. noun, verb, preposition...).
As for your second question, print is indeed instant. However, you could use the time
module to get the wanted effect. One example:
import time
import sys
sentence = "The quick brown fox jumps over the lazy dog"
for c in sentence:
sys.stdout.write(c)
time.sleep(0.1)
You can adjust the 0.1 to your liking - it's the sleep time in seconds. You could even make it random within some interval. For the reason I used sys.stdout.write
as opposed to print c
or print c,
see this question.