הוא כועס כי יש יותר מדי רעש במשרד.

In present-tense Hebrew, the verb to be is usually omitted. So הוא כועס literally looks like he angry, but it means he is angry.

You do use forms of to be in other tenses:

• הוא היה כועס = he was angry
• הוא יהיה כועס = he will be angry

כועס is the masculine singular present form of לכעוס, which means to be angry or to get angry. In a sentence like this, it works a lot like an adjective.

It changes to match gender and number:

• הוא כועס = he is angry
• היא כועסת = she is angry
• הם כועסים = they are angry
• הן כועסות = they are angry

Here, כי means because.

So:

• הוא כועס כי... = He is angry because...

Hebrew also has other ways to say because, such as מפני ש־ or בגלל ש־, but כי is very common and natural.

יש means there is or there are. Hebrew uses it to express existence.

So:

• יש רעש = there is noise
• יש יותר מדי רעש = there is too much noise

English uses there is, but Hebrew uses the single word יש.

יותר מדי means too much or too many. Literally, it is something like more than enough.

Examples:

• יותר מדי רעש = too much noise
• יותר מדי אנשים = too many people
• יותר מדי עבודה = too much work

So in this sentence, יש יותר מדי רעש means there is too much noise.

Because רעש is usually treated as an uncountable noun, like noise in English.

So Hebrew normally says:

• יותר מדי רעש = too much noise

not a plural form meaning noises. If you want to talk about separate sounds or noises, Hebrew would usually use a different wording depending on the context.

Hebrew often attaches prepositions directly to the following noun.

Here:

• ב־ = in / at
• משרד = office

So:

• במשרד = in an office / in the office

This is completely normal in Hebrew. The preposition is a prefix, not a separate word.

Without vowel marks, the spelling במשרד can represent either one.

• במשרד = be-misrad = in an office
• במשרד = ba-misrad = in the office

In everyday Hebrew, vowel marks are usually not written, so context tells you which meaning is intended. In this sentence, in the office is probably the most natural interpretation.

Yes. Hebrew word order is somewhat flexible.

The given sentence is a neutral, natural order:

• הוא כועס כי יש יותר מדי רעש במשרד.

You could also say:

• הוא כועס כי במשרד יש יותר מדי רעש.

That version puts a bit more focus on in the office. Both are grammatical; the original is simply smoother and more neutral for everyday speech.