صديقي يتذكر دائما عنوان الشركة، وأنا أتذكره أحيانا فقط.

In Arabic, possession is often shown by attaching a pronoun directly to the noun.

• صديق = friend
• ـي = my

So:

• صديقي = my friend

This is much more natural in Arabic than using a separate word for my.

A useful comparison:

• صديق = a friend / friend
• صديقي = my friend
• صديقك = your friend
• صديقه = his friend

Also, صديقي normally refers to a male friend. For my female friend, you would usually say صديقتي.

Arabic allows more than one natural word order.

Here, صديقي يتذكر starts with the subject:

• صديقي = my friend
• يتذكر = remembers

This structure makes my friend the topic, a bit like:

• As for my friend, he always remembers...

You could also say:

• يتذكر صديقي دائما عنوان الشركة

That is also grammatical, but it feels a little different in emphasis. Starting with صديقي gives it a clearer contrast with the second half of the sentence: وأنا...

The verb form itself tells you the subject.

• يتذكر = he remembers
• أتذكر = I remember

The important prefixes here are:

• يـ in يتذكر → usually he
• أ in أتذكر → I

So Arabic often does not need a separate subject pronoun, because the verb already tells you who is acting.

In this sentence:

• صديقي يتذكر = my friend remembers
• أنا أتذكره = I remember it

Great question. Yes, أنا is not strictly necessary here, because أتذكر already shows I.

So both are possible:

• وأنا أتذكره أحيانا فقط
• وأتذكره أحيانا فقط

Including أنا adds emphasis or contrast. It sounds like:

• ...and I, on the other hand, only remember it sometimes.

So أنا is there mainly for contrast with صديقي.

Yes. تذكّر / يتذكّر is a very common MSA verb meaning to remember or to recall.

This sentence uses:

• يتذكر = he remembers
• أتذكر = I remember

You may also see the related verb ذَكَرَ / يَذْكُرُ. That often means to mention, though in some contexts it can also mean to remember. For a learner, تذكّر is the clearer, safer everyday choice for remember.

Because this is an iḍāfa structure, often called a possessive construction.

• عنوان = address
• الشركة = the company

Together:

• عنوان الشركة = the company’s address

In an iḍāfa:

1. the first noun usually does not take الـ
2. the second noun shows who owns or specifies the first noun

So:

• عنوان الشركة = the address of the company / the company’s address

Even though عنوان has no الـ, the whole phrase is definite because الشركة is definite.

The ـه is an attached object pronoun meaning him or it.

Here it means it, and it refers back to:

• عنوان الشركة = the company’s address

More specifically, the pronoun agrees with عنوان, which is grammatically masculine singular, so Arabic uses ـه.

So:

• أتذكره = I remember it

If the thing being referred to were feminine, Arabic would use ـها instead.

These are adverbs of frequency.

• دائما = always
• أحيانا = sometimes
• فقط = only

So:

• يتذكر دائما = always remembers
• أتذكره أحيانا فقط = I remember it only sometimes

Their position is natural in Arabic, but adverbs can sometimes move around for style or emphasis. The version in your sentence is very idiomatic and clear.

The word فقط strengthens the limitation:

• أحيانا = sometimes
• أحيانا فقط = only sometimes

So the second half contrasts nicely with the first:

• He always remembers
• I only sometimes remember

Yes. In this sentence, فقط means only or just.

So:

• وأنا أتذكره أحيانا فقط = and I remember it only sometimes

Without فقط, the sentence would still make sense:

• وأنا أتذكره أحيانا = and I remember it sometimes

But فقط adds the idea of limitation: not often, just sometimes.

Yes. In normal Arabic writing, short vowels and many grammatical endings are usually not written.

A fully vocalized version would look something like:

• صديقي يتذكّر دائمًا عنوانَ الشركةِ، وأنا أتذكّره أحيانًا فقط.

A few things to notice:

• عنوانَ has fatḥa because it is the direct object of يتذكر
• الشركةِ has kasra because it is the second part of an iḍāfa
• دائمًا and أحيانًا are commonly written with tanwīn fatḥ

In everyday texts, learners usually see the unvowelled form:

• صديقي يتذكر دائما عنوان الشركة، وأنا أتذكره أحيانا فقط.

So don’t worry if the endings are not written out; that is normal in MSA.