Can this be a valid sentence?

Question

私はたくさんのパンを食べますとたくさんの水を飲むます Yes, we can omit the 私は but the rest just sounds weird to me. This is what it should mean: I eat a lot of bread and drink a lot of water. Thank you!

Answer 1

This sentence does not have intended meaning. と can be used to create list of nouns, but NOT to create list of causally-unrelated clauses containing verbs.

For conjoining of multiple causally-unrelated clauses, verbs in non-last clauses should be either in [連用形]{れんようけい}/Continuative form _{(this may sound more formal or literary)} or 〜て form _{(called Gerund or Subordinative Converb by some linguists)}:

私はたくさんのパンを食べたくさんの水を飲みます

私はたくさんのパンを食べてたくさんの水を飲みます

There are situations where と can conjoin clauses, but then it is some type of conditional ("if", "when"). I think that original sentence from this question would mean "If I eat a lot of bread, then I drink a lot of water.".

Answer 2

Your example sentence reads,

If I eat a lot of bread, then I drink a lot of water.

と does not work as the conjunction and to connect verbs. と only means and when connecting nouns together. When と follows a verb, it generally means "whenever" or "if".

To say "I eat a lot of bread and I drink a lot of water", there are a number of choices.

You could just say,

パンをたくさん食べます。水をたくさん飲みます。

パンをたくさん食べますし。水をたくさん飲みます。

パンをたくさん食べて水をたくさん飲みます

though this last example sounds like you first eat a lot of bread and then drink a lot of water.

You could also say,

パンをたくさん食べ 水をたくさん飲みます