هو يكره الطقس السيئ.

A quick breakdown:

• هو = the independent pronoun he
• يكره = he hates / he dislikes
• الطقس = the weather
• السيئ = the bad → here it describes weather, so bad weather

So grammatically, you have:

• subject pronoun: هو
• verb: يكره
• direct object: الطقس السيئ

Yes, you can absolutely say يكره الطقس السيئ.

In Arabic, the verb already tells you the subject here:

• يكره = he hates

So هو is often optional unless you want:

• extra clarity
• emphasis
• contrast, as in هو يكره الطقس السيئ، لكنها تحبه = He hates bad weather, but she likes it

This is very common in Arabic: subject pronouns are often dropped when the verb already makes the subject clear.

The يـ is part of the present/imperfect tense conjugation.

For many verbs in the imperfect, Arabic uses prefixes to show the subject. Here:

• يكره = he hates
• أكره = I hate
• تكره = she hates or you (masc.) hate
• نكره = we hate

So in this sentence, يـ tells you the subject is he (or sometimes it, depending on context).

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

So:

• الطقس السيئ = literally the weather the-bad
• natural English = the bad weather

This is one of the biggest word-order differences from English. In Arabic:

• noun first
• adjective second

Examples:

• الكتاب الجديد = the new book
• البيت الكبير = the big house

Because Arabic adjectives must match the noun in definiteness.

Here:

• الطقس = the weather (definite)
• so the adjective must also be definite:
• السيئ = the bad

That is why Arabic says:

• الطقس السيئ = the bad weather

Compare:

• طقس سيئ = bad weather / a bad weather condition in a more indefinite sense
• الطقس السيئ = the bad weather

So if the noun has الـ, the adjective usually does too.

Because it has to agree with الطقس.

Arabic adjectives agree with the noun they describe in:

• gender
• number
• definiteness
• and, in fully vocalized Arabic, case

Here, الطقس is grammatically:

• masculine
• singular
• definite

So the adjective must match:

• السيئ

Even if something is not biologically male or female, Arabic still assigns it a grammatical gender. طقس is grammatically masculine.

Yes. In fully vocalized Modern Standard Arabic, the sentence would be:

هُوَ يَكْرَهُ الطَّقْسَ السَّيِّئَ

Those final vowels show case and mood:

• يكرهُ ends in ـُ because it is an indicative imperfect verb
• الطقسَ ends in ـَ because it is the direct object, so it is accusative
• السيئَ also ends in ـَ because it is the adjective describing that accusative noun

In normal everyday writing, these short vowels are usually not written, so you usually see:

هو يكره الطقس السيئ

It is pronounced roughly as-sayyiʾ.

A few important points:

• The الـ before س is pronounced with assimilation, because س is a sun letter
• So ال is not pronounced al here; it sounds more like as-
• The يّ has a doubled y sound because of the shadda
• The final ء is a hamza, a glottal stop

So:

• السيئ ≈ as-sayyiʾ

And the phrase:

• الطقس السيئ ≈ aṭ-ṭaqs as-sayyiʾ

Often, yes — يكره can sound fairly strong, like hate or strongly dislike.

But in real usage, the exact force depends on context. It can sometimes be understood as:

• hates
• dislikes very much
• can't stand

If you want something milder, Arabic often uses:

• لا يحب = does not like

So:

• هو يكره الطقس السيئ = stronger
• هو لا يحب الطقس السيئ = milder

You would change both the pronoun and the verb form.

For example:

• أنا أكره الطقس السيئ = I hate bad weather
• أنتَ تكره الطقس السيئ = You (masc.) hate bad weather
• أنتِ تكرهين الطقس السيئ = You (fem.) hate bad weather
• هي تكره الطقس السيئ = She hates bad weather
• نحن نكره الطقس السيئ = We hate bad weather

This is useful because it shows that the verb form carries a lot of grammatical information in Arabic.