أريد أن أشتري هدية صغيرة لجاري قبل الزيارة.

Because Arabic verbs already show the subject.

• أريد = I want
• أشتري = I buy / I am buying (and here, after أن, to buy)

So the sentence does not need أنا. You can say أنا أريد..., but that usually adds emphasis, like I want...

In Modern Standard Arabic, after verbs like أريد (I want), Arabic usually uses:

• أن + present/imperfect verb

So:

• أريد أن أشتري = I want to buy

This is one of the main ways Arabic expresses the idea of the English infinitive to buy.

Grammatically, it does change, but in normal unvocalized writing you usually cannot see it clearly.

After أن, the imperfect verb becomes subjunctive (منصوب).
So أشتري is formally in the subjunctive here.

With full vowel marks, it can be written:

• أَشْتَرِيَ

But in everyday Arabic writing, that final case/mood marking is usually not shown, so it looks the same as أشتري.

Not in the same way English does.

Arabic often uses:

• أن + imperfect verb
  as in أريد أن أشتري

There is also a verbal noun (مصدر) that can sometimes do a similar job:

• أريد شراءَ هديةٍ صغيرةٍ...
• literally: I want the buying of a small gift...

That version is correct, but أريد أن أشتري is very natural and straightforward for learners.

Because in Arabic, adjectives normally come after the noun they describe.

So:

• هدية صغيرة = a small gift

not the other way around.

This is the normal noun + adjective order in Arabic.

Because هدية is a feminine noun, so the adjective must also be feminine.

Arabic adjectives agree with the noun in:

• gender
• number
• definiteness
• case

So:

• هدية = feminine singular
• صغيرة = feminine singular

If the noun were masculine, you would use صغير.

The final ة is called تاء مربوطة.

It often marks a feminine noun, and it is usually pronounced:

• -a / -ah when pausing

So هدية is pronounced roughly hadiyya(h).

When grammar connects it closely to what follows, that ending can sound like t in some contexts, but in this sentence you can think of it simply as hadiyyah.

لِـ is a preposition meaning for or to.

So:

• لجاري = for my neighbor

In Arabic, short prepositions like بـ, لـ, and كـ are usually written attached to the following word.

So it is:

• لِ + جاري = لجاري

not written as a separate word.

The basic noun is:

• جار = neighbor

To say my neighbor, Arabic adds the possessive suffix:

• -ي = my

So:

• جار
  • ي = جاري = my neighbor

Then with the preposition لِـ:

• لجاري = for my neighbor

If the neighbor were specifically female, you would usually say:

• لجارتي = for my female neighbor

Because الـ makes the noun definite:

• زيارة = a visit / visiting
• الزيارة = the visit

Using الزيارة suggests a specific visit already known from context, such as a planned visit.

So the sentence implies something like:

• before the visit
• before our visit
• before the upcoming visit

If you meant before a visit in a more general sense, you would more likely use an indefinite form such as قبل زيارةٍ.

قبل means before.

In this sentence it introduces the time expression:

• قبل الزيارة = before the visit

Grammatically, قبل is often treated like an adverb/noun of time that takes the following noun in the genitive.

So with full vowel marks:

• قَبْلَ الزِّيَارَةِ

Here:

• قبلَ is in the accusative as an adverbial expression
• الزيارةِ is genitive after it

In writing, it is always الزيارة, but in pronunciation the ل of الـ is assimilated because ز is a sun letter.

So it is pronounced roughly:

• az-ziyārah

not al-ziyārah.

This happens only in pronunciation, not spelling.

One fully vocalized version is:

أُرِيدُ أَنْ أَشْتَرِيَ هَدِيَّةً صَغِيرَةً لِجَارِي قَبْلَ الزِّيَارَةِ.

A few useful things to notice:

• أُرِيدُ: the main verb, with -u ending
• أَنْ أَشْتَرِيَ: أن
  • subjunctive verb
• هَدِيَّةً صَغِيرَةً: both are accusative because هدية is the direct object and صغيرة agrees with it
• لِجَارِي: after a preposition
• قَبْلَ الزِّيَارَةِ: before the visit, with الزيارةِ in the genitive

A rough transliteration would be:

urīdu an ashtariya hadiyyatan ṣaghīratan lijārī qabla z-ziyārah