הוא מסתכל על מנעול הצירופים כאילו הוא יודע את הצופן.

מסתכל is the masculine singular present-tense form of להסתכל (to look / to look at).

Because the subject is הוא (he), Hebrew uses the masculine singular form.

Also, Hebrew present tense often covers both:

• a simple present meaning: he looks
• a present progressive meaning: he is looking

So הוא מסתכל can mean either one, and context tells you which is more natural. In this sentence, he is looking is probably the best English rendering.

Because להסתכל normally takes the preposition על when it means to look at something.

So:

• להסתכל על משהו = to look at something

This is just the standard pattern of the verb, much like English look at requires at.

מנעול הצירופים means the combination lock.

Literally, it is something like lock of the combinations. This is a Hebrew noun pattern called the construct state (סמיכות).

In this pattern:

• the first noun usually does not take ה־
• the second noun can carry the definiteness for the whole phrase

So:

• מנעול צירופים = a combination lock
• מנעול הצירופים = the combination lock

Even though מנעול itself has no ה־, the whole phrase is definite because הצירופים is definite.

צירוף means combination or combining arrangement, and צירופים is the plural.

In the fixed expression מנעול צירופים, Hebrew uses the plural where English uses the singular adjective-like noun combination. So the standard Hebrew term is literally closer to lock of combinations, but idiomatically it simply means combination lock.

This is normal and not something you need to translate word-for-word into English.

Here כאילו means as if.

It introduces a comparison between appearance and reality:

• הוא מסתכל על מנעול הצירופים = he is looking at the combination lock
• כאילו הוא יודע את הצופן = as if he knows the code

So it gives the sense of he looks at it as though he knows how to open it.

A useful note: in colloquial Hebrew, כאילו can also mean something like like as a filler word, but that is not what it means in this sentence.

Because כאילו הוא יודע את הצופן is a new clause, and Hebrew very naturally states the subject again.

So the structure is:

• הוא מסתכל...
• כאילו הוא יודע...

Also, in the present tense, Hebrew verbs do not show person clearly. For example, יודע can mean:

• I know with אני
• you know with אתה
• he knows with הוא

Because of that, the pronoun is often stated to make the subject clear.

יודע is the masculine singular present-tense form of לדעת (to know).

It agrees with הוא, so:

• הוא יודע = he knows

Other present-tense forms are:

• יודעת = feminine singular
• יודעים = masculine/mixed plural
• יודעות = feminine plural

את marks a definite direct object.

In this sentence:

• הצופן = the code
• it is definite because of ה־
• therefore Hebrew uses את

So:

• הוא יודע את הצופן = he knows the code

But:

• הוא יודע צופן would be unnatural here, and in general if the object were indefinite, את would not be used

Important: את usually is not translated into English. It is a grammatical marker.

Because the sentence is talking about a specific code: the code.

So:

• צופן = a code / cipher
• הצופן = the code / the cipher

That matches the idea that he is looking at the lock as if he knows the exact code needed for it.

They are similar, but not always identical in tone.

• צופן often means code or cipher, and can sound a bit more formal or literary
• קוד is a very common modern word for code
• סיסמה means password, not the same thing

In this sentence, צופן works well because it fits the idea of a lock and its secret combination/code. A speaker might also say קוד in everyday speech, but צופן is perfectly natural here.