After teaching English here in Japan for nearly 20 years, I've noticed that there are some common mistakes that keep coming up. Fighting off the urge to roll your eyes, a teacher needs to understand this is a teachable moment. This is like finding a nugget of gold while swimming in the river. Because they are common errors, we can make a dent in this fault in the local language skills by explaining why they are wrong.
Here are a few that have come across my path in the last week or so;
"I choiced to go to school in Kansai." -> It is common to hear students mistakenly use 'choice' as a verb. I will challenge them; choice is a noun, what is the verb? If they can't come up with it, I'll introduce choose-chose-chosen. (Success/succeed has the same problem)
Safety Driver. In a similar vein, for years the Japanese police and other safety-concerned agencies have made stickers to put on cars saying 'safety driver'. Safety is a noun- safe is the correct adjective.
Do you drive MY CAR? Rather than saying 'your own' they often will staple 'my' in front of words like 'home' or 'car' for instance. I think a few clever advertising campaigns are to blame for this problem, but, hey, let's remember that 'my' means that is the speaker's own possession.
I overworked yesterday. While many may argue that it is overworking, the truth is, what the speaker wants to say is, "I worked overtime yesterday."
These are just a few examples, but there are a lot more. I will keep note as I encounter them and post again on this topic in the future.