יש מים מתחת לכיור, ואולי יש שם נזילה.

יש is the Hebrew word used to express existence: there is or there are.
So יש מים means there is/there are water under the sink, and later יש שם נזילה means there is a leak there.

It does not change for singular vs. plural:

• יש ספר = there is a book
• יש ספרים = there are books

Because the sentence is making two separate existence statements:

1. יש מים מתחת לכיור = there is water under the sink
2. ואולי יש שם נזילה = and maybe there is a leak there

Hebrew normally repeats יש in each clause rather than relying on the first one to cover both ideas.

מים is one of those Hebrew nouns that is grammatically plural in form even though in English it is usually translated as the mass noun water.

So although the meaning is just water, the word itself looks plural. In other contexts, it often takes plural agreement:

• מים קרים = cold water

But with יש, you do not have to worry about agreement, because יש stays the same.

Because מתחת usually connects to the following noun with ל־.
The pattern is:

• מתחת ל־... = under ...
• מעל ל־... = above ...
• ליד ... is different and does not use this pattern

So מתחת לכיור literally follows the normal Hebrew structure for under the sink.

Because in Hebrew, prepositions like ל־ often combine with the definite article ה־.

So:

• כיור = sink
• הכיור = the sink
• לכיור can represent ל + הכיור in normal spelling

In other words, לכיור here means to/at the sink as part of the expression מתחת לכיור = under the sink.

Here, שם means there.

This same word can also mean name, which can confuse learners. The meaning comes from context:

• השם שלי... = my name...
• יש שם נזילה = there is a leak there

So in this sentence, it is definitely the location word there.

נזילה means a leak, especially the kind you might have in plumbing, a sink, or a pipe.

It comes from the root נ־ז־ל, which is related to dripping or flowing. So it is a very natural word in a sentence about water under a sink.

Because Hebrew does not have an indefinite article like English a/an.

So:

• נזילה = a leak / leak
• הנזילה = the leak

Since the sentence says נזילה without ה־, it is indefinite: a leak.

ו־ is the Hebrew word for and, and it is normally attached directly to the next word.

So:

• אולי = maybe / perhaps
• ואולי = and maybe / and perhaps

This attachment is completely normal in Hebrew:

• וספר = and a book
• והילד = and the boy
• ואולי = and maybe

כיור is usually masculine.

It does not matter in this sentence because there is no adjective describing the sink and no verb agreeing with it in a way that shows gender. But if you added an adjective, you would normally use the masculine form:

• כיור גדול = a big sink

Yes. Hebrew allows some flexibility here.

For example, you could also say:

• יש מים מתחת לכיור, ואולי יש נזילה שם
• יש מים מתחת לכיור, ואולי שם יש נזילה

These versions are all understandable, but the original ואולי יש שם נזילה is very natural. It keeps the focus on the existence of the leak, with שם adding the location afterward.