קשה לפתוח את המנעול הישן, אבל מחר נתקן אותו.

In this sentence, קשה means hard or difficult, and it is being used in an impersonal pattern:

קשה + infinitive

So:

קשה לפתוח... = It is hard to open...

Hebrew often uses this structure where English uses it is + adjective + to + verb.

Other examples:

• קל להבין = It is easy to understand
• חשוב לדעת = It is important to know
• נעים לפגוש אותך = It is pleasant to meet you

So קשה here does not mean that some person is hard; it means that the action is difficult.

לפתוח is the infinitive form of the verb פתח, meaning to open.

After words like קשה, Hebrew usually uses the infinitive:

• קשה לפתוח = hard to open
• קל לעשות = easy to do
• אסור להיכנס = forbidden to enter

So לפתוח is used because the sentence is talking about the action in a general way: opening the old lock.

את is the marker of a definite direct object.

In Hebrew, when the direct object is definite, you usually put את before it.

Here:

• המנעול הישן = the old lock
• because it is definite, Hebrew uses את
• so: לפתוח את המנעול הישן = to open the old lock

Compare:

• לפתוח מנעול = to open a lock
• לפתוח את המנעול = to open the lock

A very common learner mistake is forgetting את before a definite direct object.

In Hebrew, adjectives usually come after the noun they describe.

So:

• מנעול ישן = an old lock
• המנעול הישן = the old lock

This is the normal Hebrew word order:

noun + adjective

Unlike English, where the adjective usually comes before the noun.

Because in Hebrew, when a noun is definite and it has an adjective, the adjective usually becomes definite too.

So:

• מנעול ישן = an old lock
• המנעול הישן = the old lock

Both the noun and the adjective take ה־.

This is a very important Hebrew pattern:

• הספר החדש = the new book
• הבית הגדול = the big house
• הילדה הקטנה = the little girl

So המנעול הישן literally has the on both parts, but in English we still just say the old lock.

You know it from the way other words agree with it.

Here, the adjective is הישן, which is masculine singular.
Also, the pronoun אותו later in the sentence is masculine singular too.

So:

• מנעול = masculine singular noun
• ישן = masculine singular adjective
• אותו = masculine singular object pronoun

If it were feminine, you would expect forms like ישנה and אותה instead.

נתקן means we will fix or we will repair.

It comes from the root connected with fixing / repairing, and it is in the future tense, 1st person plural:

• נתקן = we will fix

So:

• מחר נתקן אותו = tomorrow we will fix it

In Hebrew, the subject pronoun אנחנו is often omitted because the verb form already tells you who the subject is.

Because Hebrew verbs usually already show the subject.

נתקן already means we will fix, so אנחנו is not necessary.

You could say:

• מחר נתקן אותו or
• מחר אנחנו נתקן אותו

Both are possible, but the first one is more natural in many contexts.

This is very common in Hebrew:

• אלך = I will go
• תבוא = you will come
• נשמע = we will hear / we will listen

אותו means him or it, depending on context.

Here it means it, because it refers back to המנעול = the lock.

Hebrew object pronouns reflect grammatical gender:

• אותו = him / it for a masculine noun
• אותה = her / it for a feminine noun
• אותם = them masculine / mixed
• אותן = them feminine

So in this sentence:

• המנעול is masculine
• therefore אותו is used

You could say אבל מחר נתקן, and in context people might understand what you mean. But אותו is used to make the object explicit: we’ll fix it.

So:

• אבל מחר נתקן = but tomorrow we’ll fix
• אבל מחר נתקן אותו = but tomorrow we’ll fix it

Hebrew often uses an object pronoun like this when referring back to something already mentioned.

Yes. מחר means tomorrow, and its placement here is very natural:

אבל מחר נתקן אותו = but tomorrow we will fix it

Hebrew word order is somewhat flexible, so you may also hear:

• אבל נתקן אותו מחר

Both are possible, though the emphasis can shift slightly:

• מחר נתקן אותו emphasizes tomorrow
• נתקן אותו מחר sounds a little more like a neutral statement about when it will happen

אבל means but, and it connects two contrasting ideas:

• קשה לפתוח את המנעול הישן = it is hard to open the old lock
• אבל מחר נתקן אותו = but tomorrow we will fix it

So the contrast is:

• right now, opening it is difficult
• however, there is a solution coming tomorrow

This is a very common use of אבל in Hebrew, just like but in English.

Yes, that is a very natural English rendering of the same idea.

Hebrew says:

• קשה לפתוח את המנעול הישן

Literally, the structure is closer to:

• It is hard to open the old lock

But in English, a smoother version can be:

• The old lock is hard to open

So although the Hebrew grammar is built differently, the meaning is the same.

Basically, ישן means old, but depending on context it can suggest more than just age.

In this sentence, המנעול הישן could simply mean:

• an old lock

But because the next clause says:

• אבל מחר נתקן אותו = but tomorrow we’ll fix it

it also suggests that the lock may be old enough to be problematic, worn, or damaged.

So the adjective itself just means old, but the whole sentence gives it a stronger practical sense.