תלחץ על המקש הירוק ותחכה עד שהעמוד ייפתח.

In everyday Hebrew, the 2nd-person future is very often used to give instructions or commands.

So:

• תלחץ literally looks like you will press
• תחכה literally looks like you will wait

But in this context they mean:

• press
• wait

This is very common in spoken Hebrew and in practical instructions. The more formal imperative forms would be לחץ and חכה.

The forms תלחץ and תחכה are 2nd person masculine singular, so the sentence is speaking to one male.

If you were speaking to:

• one female: תלחצי על המקש הירוק ותחכי עד שהעמוד ייפתח
• more than one person: תלחצו על המקש הירוק ותחכו עד שהעמוד ייפתח

So Hebrew makes gender and number visible in the verb.

Because the verb ללחוץ normally goes with the preposition על when you mean press on / press a button or key.

So Hebrew says:

• ללחוץ על המקש = to press the key/button

Since the noun comes after על, you do not use את.

So:

• לחצתי על הכפתור = I pressed the button
• not לחצתי את הכפתור

מקש means a key or button, often something technical or mechanical, such as:

• a keyboard key
• a remote-control button
• a device key

כפתור is a more general word for button.

In many contexts they can overlap, but מקש often sounds a bit more like a specific control key, while כפתור is broader.

In Hebrew, adjectives usually come after the noun.

So:

• מקש ירוק = a green key/button
• המקש הירוק = the green key/button

Also, when the noun is definite, the adjective must be definite too. That is why both words have ה:

• המקש = the key
• הירוק = the green

This matching is very important in Hebrew.

עד ש־ means until when it is followed by a whole clause.

So:

• עד שהעמוד ייפתח = until the page opens / until the page will open

The ש־ is a linker meaning something like that in structure, though you usually do not translate it directly into English.

Also:

• ש + העמוד becomes שהעמוד

Compare:

• עד מחר = until tomorrow
• עד שהעמוד ייפתח = until the page opens

That is a very common difference between Hebrew and English.

In Hebrew, when the action is still in the future, a subordinate clause after words like עד ש־ often uses the future tense:

• עד שהעמוד ייפתח

In natural English, we usually translate that with the present:

• until the page opens

So the Hebrew is perfectly normal even though a word-for-word translation sounds like until the page will open.

ייפתח comes from the root פ־ת־ח and is in the Nifal pattern.

Here it means:

• will open
• will be opened

It focuses on the page becoming open, rather than on the person doing the opening.

That is very natural in Hebrew with things like:

• הדלת תיפתח = the door will open
• הקובץ ייפתח = the file will open
• העמוד ייפתח = the page will open

So this is not really someone will open the page, but rather the page will open.

In unpointed modern Hebrew spelling, forms like this are often written with two י letters to show the Nifal future pattern.

So:

• ייפתח is the standard spelling here

One י belongs to the future prefix, and the other helps represent the vowel pattern in normal unvocalized writing.

This also helps distinguish it from other forms that might otherwise look similar.

A simple pronunciation guide would be:

til-khatz al ha-ma-KASH ha-ya-ROK ve-te-kha-KE ad she-ha-a-MUD yi-pa-TAKH

A smoother transliteration: tilkhatz al hamakash hayarok vetekhake ad sheha'amud yipatach

A few notes:

• ח sounds like kh in Bach or Scottish loch
• תלחץ = tilkhatz
• תחכה = tekhake
• ייפתח = yipatach

The stress is usually near the end of each of those verbs.