he can does it vs he can do it

Some examples from the web:

• He's studying as hard as he can, but it doesn't seem to matter.

Some examples from the web:

• If my father wants to rehab his image, he can do it himself.
• If he sensed you once, he can do it again.
• If he wants to take it up with President Taylor, he can do it when he's...
• But my question is whether he can do it or not.
• I need to know that he can do it again, or we all die.
• I think if Raj wants to break up with a girl, he can do it.
• Chambers called the cops at the Gatsby party and he can do it again.
• If Nick wants to talk to me he can do it himself.
• Almost as ugly as what Mason wants to do to us is the fact that he can do it with the tacit agreement of people sworn to uphold the law.
• He can do it again if he has to.
• When he wants to go into a climb, he can do it.
• I truly believe he can do it.
• I don't think he can do it.
• Culvahouse says he can do it, so...
• But if he can do it...
• It's the last night he can do it.
• Always... that he can do it.
• Tell the pilot he can do it.
• More power to him if he can do it without us.
• I'm surprised he can do it.