يفتح صديقي الباب بقوة.

Because this is a very common Arabic sentence pattern: verb + subject + object.

So:

• يفتح = opens / is opening
• صديقي = my friend
• الباب = the door
• بقوة = forcefully / with force

This is called a verbal sentence in Arabic.
Arabic can also say:

صديقي يفتح الباب بقوة

That version is more like My friend is opening the door, with slightly more focus on my friend. Both are correct.

يفتح is the imperfect form of the verb فتح.

In Modern Standard Arabic, the imperfect can express several meanings depending on context, including:

• he opens
• he is opening
• he does open

So يفتح does not only mean one single English tense. Context tells you whether it is present, habitual, or ongoing.

Its base verb is:

• فتح = to open

And here:

• يـ at the beginning often marks he in the imperfect
• يفتح = he opens / he is opening

Because the ـي at the end is a possessive suffix meaning my.

So:

• صديق = friend
• صديقي = my friend

This is a very common Arabic pattern:

• كتابي = my book
• بيتي = my house
• أخي = my brother

So صديقي is not just friend; it specifically means my friend.

Because صديقي is already definite by possession.

In Arabic, a noun becomes definite not only with الـ but also when it is possessed.
So صديقي already means my friend, which is definite.

That is why you do not say:

• الصديقي for my friend

Instead, you simply say:

• صديقي

الباب has الـ, the definite article, so it means the door.

Compare:

• باب = a door
• الباب = the door

So in this sentence, the object is a specific door, not just any door.

In a normal Arabic verbal sentence, the noun right after the verb is usually the subject, and the next noun is often the object.

So:

• يفتح = verb
• صديقي = subject
• الباب = object

If the text is fully vowelled, the grammar becomes even clearer:

• يَفْتَحُ صَدِيقِي الْبَابَ بِقُوَّةٍ

Here البابَ has the accusative ending, marking it as the object.

In everyday writing, short vowels are usually omitted, so learners often depend on:

1. word order
2. sentence pattern
3. meaning

بقوة literally means with force.

It is made of:

• بـ = with / by
• قوة = force, strength

Together:

• بقوة = with force, strongly, forcefully

In English, we often translate this more naturally as:

• forcefully
• hard
• with force

So Arabic often uses a preposition + noun where English might prefer an adverb.

The preposition بـ often means:

• with
• by
• using

In this sentence, it describes the manner of the action:

• يفتح الباب بقوة = he opens the door with force

Arabic commonly expresses manner this way. Some similar examples are:

• بسرعة = بسرعة = quickly, literally with speed
• بعناية = carefully, literally with care
• بهدوء = quietly, literally with calmness

So بقوة fits a very common Arabic structure.

A fully vowelled version is:

يَفْتَحُ صَدِيقِي الْبَابَ بِقُوَّةٍ

This shows details that are usually omitted in normal writing:

• يَفْتَحُ = the verb with its final vowel
• صَدِيقِي = my friend
• الْبَابَ = the door, marked as the object
• بِقُوَّةٍ = with force

In most real-world Arabic texts, these short vowels are not written, so you usually see:

يفتح صديقي الباب بقوة

Because the word contains a shadda on و in the fully vowelled form:

قُوَّة

That means the w sound is doubled or held slightly longer.

So it is pronounced roughly like:

• quw-wa

not just:

• qu-wa

This doubling is an important part of the word’s structure.

Yes. Arabic often allows a range of natural English translations.

Depending on context, يفتح صديقي الباب بقوة could be understood as:

• My friend opens the door forcefully
• My friend is opening the door forcefully
• My friend opens the door with force
• My friend pushes the door open hard
  (if the context suggests that)

The basic grammar stays the same; English just chooses the most natural wording for the situation.