Putting articles: the or a

The plausibility of such statements is questionable. Do you propose that you have answered your phone, and that you are telling your caller what you are doing right now? Either the or a can be used in such sentences. The problem is in imagining a situation in which you would make such a statement. Saying the river or the lake implies that your interlocutor will know to which river or lake you refer. Saying a river or a lake begs the question of which river or lake you are referring to. I cannot imagine a situation in which a native speaker of English would make any of those statements.

How would you say, or how would one say, and, which would be better.

Helen, "the" implies I know which river and "a," I mightn't

If my father spoke of dismissing someone contemptuously, he would say "I'll tell him to go and jump in the lake", and if someone had tried to trick or betray him he'd say "he tried to sell me down the river". The identities of these watery milieux were, I suppose, previously known, or else obvious to the listener (me), as "the lake into which fools should jump", and "The river down which tricksters try to sell us". Not connected, I know, but to my father (and now me, I realise) "up the Swanee" was a very bad place to end up.

"I am fishing in the river/the lake" implies a specific river or lake.

"I am fishing in a river/a lake" does not imply a specific river or lake.

Infra isn't that pretty much what I said in #.....816 above

Yes.

Thank you again Tes, what would we do....

Thanks everybody for help!

Thanks everybody for help:-)

Entirely welcome, Helen

I am fishing in the river and I am fishing in the lake.