אני אוהב סרטים של הבמאי הזה, כי יש בהם מתח גם כשהדיאלוגים פשוטים.

Because the present-tense form of the verb agrees with the speaker’s gender.

• אני אוהב = said by a male speaker
• אני אוהבת = said by a female speaker

Hebrew present-tense verb forms often look like adjectives and change for gender and number.

Because סרטים here means films in a general sense: I like films by this director, not the films by this director.

Compare:

• אני אוהב סרטים של הבמאי הזה = I like films by this director
• אני אוהב את הסרטים של הבמאי הזה = I like the films by this director

If you add ה־ and make it definite, the sentence sounds more like you are talking about a specific set of films.

של is the common Hebrew way to show possession or association. Here it means of or by.

So:

• סרטים של הבמאי הזה = films of / by this director

In natural English, by this director sounds best, but the Hebrew structure is literally closer to films of this director.

In Hebrew, when you say this/that after a noun, the noun is usually definite, so it takes ה־.

• הבמאי הזה = this director
• הסרט הזה = this film
• הילדה הזאת = this girl

So Hebrew usually says the-director this, not director this.

Literally, יש בהם means there is in them.

In smoother English, it often means:

• they have
• there is ... in them

So:

• יש בהם מתח = there is suspense in them / they have suspense

This is a very common Hebrew pattern:

• יש בו = there is in it / he has
• יש בה = there is in her/it
• יש בהם = there is in them

בהם means in them.

It is made from the preposition ב־ meaning in plus a plural masculine pronoun ending.

Some related forms are:

• בי = in me
• בך = in you
• בו = in him / in it
• בה = in her / in it
• בנו = in us
• בהם = in them (masculine or mixed group)
• בהן = in them (feminine)

Here בהם refers back to סרטים, which is masculine plural.

Because מתח is an abstract noun meaning tension or suspense. Abstract nouns are often singular in Hebrew, just as they often are in English.

So:

• יש בהם מתח = there is suspense in them

Hebrew is not counting separate units of suspense here. It is talking about the general quality of suspense.

גם often means also, but in this sentence it works more like even.

So:

• גם כשהדיאלוגים פשוטים = even when the dialogues are simple

This is a common use of גם before a time or condition clause. It adds the idea of surprise or contrast.

כשה־ means when the...

It is made of:

• כש־ = when
• ה־ = the

So:

• כשהדיאלוגים פשוטים = when the dialogues are simple

You can think of כש as a very common everyday word meaning when. A more formal alternative is כאשר.

Because adjectives in Hebrew agree with the noun they describe.

• דיאלוגים is masculine plural
• so פשוטים must also be masculine plural

Compare:

• דיאלוג פשוט = a simple dialogue
• דיאלוגים פשוטים = simple dialogues

If the noun were feminine plural, the adjective would change too.

Because it refers to the dialogues in those films as a known set within the situation.

• כשהדיאלוגים פשוטים = when the dialogues are simple

Hebrew often uses the definite article in places where English might also use the, especially when talking about the parts or features of something already mentioned.

In the present tense, Hebrew usually does not use a word meaning am / is / are.

So:

• הדיאלוגים פשוטים literally = the dialogues simple
• natural English = the dialogues are simple

This is completely normal in Hebrew. In past and future, forms of to be can appear, but in the present they are usually omitted.

Yes. A more compact, somewhat more literary Hebrew form would be:

• סרטי הבמאי הזה

This uses the construct form, sometimes called סמיכות.

But סרטים של הבמאי הזה is very natural, common, and easy to understand, especially in everyday speech.