What are the most common tense mistakes made in English?

I'm an ESL teacher looking for display board ideas. A lot of my students say things that just can't be said in English. So far I have noticed the following sometimes written or said:

did gone 
is do

What other verb forms are semantically incorrect? I'm not looking for repeats of the same mistake, though, just some common ones using common verbs.

One common tense I error I have noticed has to do with the verb to be. Specifically, students confuse the participles. Thus, one sees, for instance, "was been" or "has being". I have also seen this: "I been..."

Most of the tense errors made by non-native speakers occur frequently with the use of irregular verbs: to be, to have, to go, etc.

One of the most common errors I have encountered is the confusion in constructing the perfect conditional tense of the verb to go. For instance, one might hear "I would have went..." instead of "I would have gone..."

I'd suggest you look to the constructions of the native language(s) of your students. It's there that you're likely to find parallels to the errors they'll make in English construction.

It's early in the day yet and I haven't had my coffee, so I can't think of too many examples. But if your students were native Russian speakers, for example, they might have a hard time remembering to put direct articles (the) in their sentences, as that's not typically in Russian.

As bikeboy389 said, you can learn a lot by looking at students' native languages. French and Italian students will sometimes say "I am born in..." when they mean "I was born in..." ("je suis ne a...", "sono nato a...").

Then there are false friends: actual is often misunderstood as meaning "current" and eventual as meaning "possible" by speakers of many European languages; German students will often confuse "when" and "if" ("wann" and "wenn" in German).