הוא אומר שהמרק מלוח מדי, ולכן עדיף שנוסיף עוד מים.

ש־ is the Hebrew subordinating word meaning that.

So:

• הוא אומר = he says
• שהמרק מלוח מדי = that the soup is too salty

In Hebrew, ש־ is often written attached directly to the next word, so שהמרק is literally that-the-soup.

This attached ש־ is extremely common in everyday Hebrew:

• אני חושב שהוא צודק = I think that he is right
• היא אמרה שנלך = She said that we will / should go

Because מלוח agrees with מרק, and מרק is a masculine noun.

• מרק = soup, masculine
• masculine adjective: מלוח
• feminine adjective: מלוחה

So:

• מרק מלוח = salty soup
• ארוחה מלוחה = salty meal

Hebrew adjectives usually match the noun in gender and number.

מדי means too in the sense of excessively.

So:

• מלוח = salty
• מלוח מדי = too salty

In Hebrew, מדי usually comes after the adjective:

• יקר מדי = too expensive
• מהיר מדי = too fast
• חם מדי = too hot

That is different from English, where too comes before the adjective.

ולכן means and therefore or simply therefore.

It is made of:

• ו־ = and
• לכן = therefore

So ולכן links the two parts of the sentence in a logical, slightly more formal way:

• He says the soup is too salty, therefore it’s better that we add more water.

Compared with אז:

• אז = so / then
• לכן / ולכן = therefore, therefore as a result

ולכן sounds a bit more explicit and slightly more formal than אז, though both are common.

In Hebrew, עדיף is often used impersonally to mean it is better / it would be better.

So:

• עדיף שנוסיף עוד מים = It’s better that we add more water

Hebrew often leaves out the equivalent of English it in this kind of sentence.

You can say זה עדיף in some contexts, but it usually means that is preferable in a more contrastive way. In this sentence, the simple impersonal עדיף is the natural choice.

Here ש־ again means that.

• עדיף = it is better
• שנוסיף עוד מים = that we add more water

So the full structure is:

• עדיף שנוסיף... = It’s better that we add...

This is a very common Hebrew pattern:

• כדאי שנלך = It’s כדאי / worthwhile that we go
• חשוב שתבוא = It’s important that you come
• חבל שאיחרנו = It’s a shame that we were late

Hebrew often uses the future tense for suggestions, intentions, and actions that should happen next.

נוסיף literally means we will add, but in context it can mean:

• we should add
• let’s add
• it would be better if we add

That is very normal in Hebrew. The future tense covers several meanings that English often separates more clearly.

So after עדיף ש־, the future form is exactly what you would expect:

• עדיף שנחכה = It’s better that we wait
• עדיף שתשאל = It’s better that you ask

נוסיף is first person plural future: we will add.

The root is י-ס-ף / הוסיף = to add.

Future forms of להוסיף include:

• אוסיף = I will add
• תוסיף = you will add / she will add
• יוסיף = he will add
• נוסיף = we will add
• תוסיפו = you (plural) will add
• יוסיפו = they will add

So שנוסיף means that we add / that we should add.

Here עוד means more / additional.

So:

• עוד מים = more water / additional water

This is different from יותר, which often means more in a comparative sense:

• יותר טוב = better / more good
• יותר גדול = bigger

A useful shortcut:

• עוד + noun often means more/additional
• יותר + adjective/adverb often means more in comparisons

So in this sentence, עוד מים is the natural choice.

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

So Hebrew says:

• מים קרים = cold water
• עוד מים = more water

You should think of מים as a fixed word. Even though it looks plural, it is just the normal word for water.

Another common noun like this is:

• שמיים = sky / heavens

Yes, and that is a very useful comparison.

• עדיף שנוסיף עוד מים = It’s better that we add more water
• עדיף להוסיף עוד מים = It’s better to add more water

Both are natural, but they feel slightly different:

• עדיף שנוסיף is more personal and includes the speaker: we should add
• עדיף להוסיף is more general or less personal: it’s better to add

In this sentence, שנוסיף works well because the speaker is clearly including themself in the action.

A natural pronunciation would be roughly:

hu omer she-ha-marak maluakh mi-day, ve-la-khen adif she-nosif od mayim

A few notes:

• הוא אומר = hu omer
• שהמרק = sheha-marak
  In fast speech, the ש־ and ה־ run together smoothly.
• מלוח = maluakh
  The final sound is the throaty Hebrew ח.
• מדי = mi-day
• ולכן = ve-lakhen
• עדיף = adif
• שנוסיף = she-nosif
• עוד מים = od mayim

It sounds mostly neutral natural Hebrew.

A few style notes:

• הוא אומר ש... is very everyday and common
• מלוח מדי is completely standard
• ולכן is a little more polished than אז, but still normal
• עדיף שנוסיף עוד מים sounds natural and idiomatic

So overall, this is a normal, correct sentence that could appear in speech or writing, with ולכן giving it a slightly more polished feel than the most casual spoken Hebrew.