while in / in

1a. All dogs must be kept on a leash while in public places.
1b. All dogs must be kept on a leash in public places.
2a. You need to leash your dog while in the park.
2b. You need to leash your dog in the park.
Are these sentences OK?
Please correct.

I think for 1a and 1b you need to use ‘on leashes’.
As regards 2a and 2b, I’m not sure whether ‘leash’ can be used as a verb.
(You can expect another explanation right now, most probably.)

You can use ‘leash’ as a verb, but it is unusual. I suggest ‘restrain’ or, more usually, ‘keep your dog on a lead’.

… more usually, ‘keep your dog on a lead’. What does it mean?

It’s what I would substitute into sentences 2 above.

“You need to keep your dog on a lead while in the park.”

Is there something else you find unclear about it?

Hi Lawrence,

In the ‘dog’ context ‘lead’ is simply another word for ‘leash’. Using the latter as a verb is not common but it does appear in a negative form as ‘unleash’ meaning ‘release’ in a figurative sense with words like ‘anger’ ‘fury’ suggesting letting emotions free.

Thank you very much, Alan, for your clarification. I had to guess it from the vague reply given to my question which, unfortunately, could not be understood. Now that you have understood and explained it, the situation is clear. Thanks also for your answer to my query related to ‘leash’ as a verb though it was referred to as ‘unusual’ (as I had thought first).

Your implied criticism is uncalled for. You asked a vague question. I asked for clarification regarding what you needed to know. I see nothing wrong in that.

Your response is uncalled for. I highlighted a phrase in your response quoted by me and asked you what you had meant by it. You could not get me. I left it at that.

Alan made it clear. I could not help acknowledging it and thanking him.

Now, is it your fancy to write something for everything? After all I made an indirect reference. You have come direct now. Why do you fumble for the feather on your head?

I write something after everything I feel needs comment, as I’ve told you many times.
TYour aim was not just to thank Alan or you wouldn’t have included the line “I had to guess it from the vague reply given to my question which, unfortunately, could not be understood.”
You saw an opportunity to criticise in a roundabout way and jumped on it. Don’t expect me to ignore it.

As I’ve told you many times, you needn’t poke your nose in every case. I did not directly refer to your ‘incomprehensibility’ after all although you could not answer my question about the highlighted phrase ‘on the lead’. The word ‘vague’ has made you intervene, I think. Anyway, LUSH.

LOL Not “every case” at all - just the ones where you make misleading statements or you ask questions.
Of course I could have answered your question - if you had bothered to explain what you found incomprehensible about it.