It is always handy to have some synonyms at hand when crafting new texts and content. One word that I often come across is "to realize" or "to realise (Brit. English) and as you should not always use the same verb(s) over and over, I want to give all you some synonyms:
ascertain, catch on (to), find out, get on (to), hear, learn, discover, see, wise (up)
Let me know if you know some different ones. And we should gather some example sentences as well.
ascertain: "Since I’m not a very good liar, most people usually find it easy to ascertain when I’m being dishonest."
to catch on (to): Then I caught on to what it was the man was saying.
discover: I discovered that speaking English was pretty easy.