All in all I think Jerry acts really well:

Example:

In today's Beaver and Andy, he does pretty well in the dinner table scene, where Ward angrily asks him if he doesn't know he got Andy started drinking again. Beaver tells Ward and June that, with all their vague references, he didn't know what was going on. Ward immediately agrees that Beaver is right.

Do you have any examples, either way?

One example I have the other way is an annoying habit he developed sometime in the fourth season, where he added "wul" (for well, I guess) before a lot of his lines.

Yeah Jerry was quite brilliant playing little Beaver. So relaxed and believable. I loved how in early seasons he would think about something and look down then up and say his line. He was excellent in his scenes with Wendell Holmes as Andy. Jerry was a real pro in the business and Tony had great admiration for him.

I liked the scene in Beaver vs. The State when he's telling the judge the truth and crying. "Larry was over and he was eating apples."

He was better when he was younger, awkward in his later years. Maybe it's me but seems as he got older, we see him more and more mouth the other actor's lines.

He was better when he was younger, awkward in his later years. Maybe it's me but seems as he got older, we see him more and more mouth the other actor's lines.
In interviews Barbara Billingsley said that Jerry was a natural as a little kid and a very good actor but that he became self conscious as he got older and as a result his acting was less natural and more stiff.

I guess when actors mouth other people's lines they don't realize viewers are watching them too not just the one speaking. I noticed Jerry briefly mouths Larry's line when they're in the library and Larry's telling him about Call of the Wild.

In Beaver's Tree I noticed (one time) Jerry mouthing while someone else was reading their part of the poem.

He was better when he was younger, awkward in his later years. Maybe it's me but seems as he got older, we see him more and more mouth the other actor's lines.

He mouths the other actors' lines more in the earlier episodes.

He mouths the other actors' lines more in the earlier episodes.

Guess I've missed it:) , been going through the series again, halfway thru the second season I haven't noticed him doing it. Maybe I picked up on it more in the later seasons because I always focus on his awkward acting. Now I'll probably notice him doing it in these early years because I'll be looking for it.

That's so funny "Focus on his awkward acting." He really repeats Penny's lines when they yell at each other face to face in Goodbye Penny or Farewell Penny.

It makes sense to me that he would mouth the poem (in Beaver's Tree) along with another actor, because he probably had to learn the whole poem. However, I had never noticed it in the other situations pointed out. Although I would think an actor would read a whole script, I didn't know they would memorize another actor's lines, as well.

There's a famous scene in The Empire Strikes Back where Harrison Ford mouths one of Carrie Fisher's lines as she's saying it, so Jerry is in good company.

Wow Harrison Ford mouthing someone's lines?? You won't see Jack Nicholson doing that. Imagine if Jack mouthed Chief's line when he says "Juicy Fruit."

I used to like this (actor?) way way back and saw him in a movie where he spent the whole time mouthing lines. I never liked him anymore.

Jerry is an excellent actor for sure!!!

It makes sense to me that he would mouth the poem (in Beaver's Tree) along with another actor, because he probably had to learn the whole poem. However, I had never noticed it in the other situations pointed out. Although I would think an actor would read a whole script, I didn't know they would memorize another actor's lines, as well.
Danny Bonaduce who played Danny Partridge on The Partridge Family has a near photographic memory and memorized the entire script. When other actors on the show messed up their lines he would correct them. I don't know if Jerry Mathers did that but he may have learned the lines that came before his lines so he wouldn't miss his cues.

Danny B was a very funny kid and very bright. Too bad he got waylaid by drugs.

In Beaver's Poster, and the next episode, the cleaning lady with Candy Moore, I noticed Jerry has started inserting the "wol" (well, I guess) in his sentences, that I mentioned in another post.

Beaver's Poster is the episode where you can tell Jerry had to re-dub his dialog in approx. the first half of the episode. It must be difficult to do that, and keep it in sync. I always wondered what happened--maybe he had laryngitis or something.

I think Danny B. is in his 50s now--hard to believe. I think he's straightened himself out. I saw him on the Part. Fam. reunion on the Today show in 2010. Shirley Jones didn't make it, and of course, neither did Susan Dey.

How can you tell Jerry had to re-dub his dialogue? In several episodes Beaver sounded all stuffed up with a cold like they made him work while sick.

It's hard to say...he "sounds" different, the inflections are like he's reading it...the expression is different, like he's not physically there. It stops right before the middle commercial break. Also, it's not in the classroom scene...that was probably filmed at a different time. This is the only episode where he re-dubs. In the football episode at the end of season 3, it's easier to tell Ward is re-dubbed, since it's not Hugh Beaumont's voice.

Maybe in Beaver's Poster Jerry was so stuffed up they had to re-dub him. Maybe he had allergies...I know I did when I was his age.

So are you saying the scene when he's talking to June and Ward about how his poster board fell apart and Ward gives him pointers? How about the scene in the beginning when he asks Ward to paint him a poster? Or when he's in the room asking Wally why he's polishing his shoes? When he leaves and says "Okay" it does sound fake. I have to check it out.

All of that is dubbed dialogue (IMO). If you have the episode from TV Land, you could replay it sometime, if you're inclined.

It returns to normal a short time after Beaver's scene with Ward in the den (when he yells, "Hey mom! Where's pop?")

Another dubbed line, I think, was in "Beaver Won't Eat." Beaver is sent to his room and while he's leaving and his back is turned you hear his voice saying something like "I'm sorry, I just don't like them" and it sounds dubbed.

Either when Beaver's "sick" due to Miss Landers being a fiancee, or when he's sick with the tonsils, June leaves his room and you hear her say, "You rest now, Beaver." I think that's dubbed, too. When they're not on camera, maybe they do that.

I never knew anything about dubbing except when Hugh is dubbed in Beaver's Team outside. You can tell it's not him.

Watching Wally's Orchid, there's a line said by Wally that is definitely redubbed, it's when he's asking Ward for extra money, it's Dow's voice, but it suddenly louder, and the words don't quite match the lips, then the level goes down and it's normal again.