أهلا وسهلا!

In fully vocalized MSA, it is أهلًا وسهلًا and is usually pronounced ʔahlan wa sahlan.

A simple guide:

• أهلًا = ah-lan
• و = wa
• سهلًا = sah-lan

The أ at the beginning is a glottal stop, like the little catch in the middle of uh-oh.
The stress is usually on the first syllable of each main word: AH-lan wa SAH-lan.

Because normal Arabic writing usually leaves out short vowels and other diacritics.

So the everyday spelling is often:

• أهلا وسهلا

But the fully marked form is:

• أهلًا وسهلًا

As a learner, you should get used to seeing both. The unvocalized version is what you will usually meet in real texts.

Individually:

• أهل relates to family, people, or one’s own folk
• سهل means easy, smooth, or plain

However, in أهلًا وسهلًا, the phrase is idiomatic. You should not translate it word for word in normal use. The whole expression functions as welcome! or you are very welcome!

Historically, it carries the sense of making someone feel among family and at ease.

In the fully vocalized form, both words appear as أهلًا and سهلًا, with the ending -an.

For a learner, the easiest way to think about this is:

• this is a fixed Arabic expression
• the -an ending is part of the standard form
• you should memorize it as أهلًا وسهلًا

If you study grammar later, you will learn that this kind of ending reflects an old accusative-style idiomatic usage. But at the beginner level, it is best treated as part of the phrase.

That final ا is mainly a spelling convention connected with the -an ending.

With full spelling and diacritics:

• أهل becomes أهلًا
• سهل becomes سهلًا

That final ا does not mean you should stretch the vowel as aa. The pronunciation is still -lan, not -laa.

Most often, أهلا وسهلا is a welcoming expression, especially when someone arrives or is being received warmly.

Depending on context:

• it can feel like welcome!
• sometimes it also works like a warm hello!

Compared with a more neutral greeting, أهلا وسهلا sounds friendlier and more hospitable.

Yes. أهلًا by itself is very common and natural.

The difference is roughly:

• أهلًا = shorter, simpler
• أهلًا وسهلًا = fuller, warmer, more welcoming

Both are useful, but the longer form often sounds especially hospitable.

It is used in both.

That is one reason it is such a useful phrase:

• it is perfectly normal in Modern Standard Arabic
• it is also widely understood and used in many spoken dialects

The exact pronunciation may vary a little from region to region, but the phrase itself is extremely common across the Arabic-speaking world.

No. أهلًا وسهلًا stays the same whether you say it to:

• one man
• one woman
• two people
• a group

So unlike some Arabic expressions, you do not need to change this one to match the person you are addressing.

In standard spelling, the word begins with أ, which is an alif with hamza above. This shows that the word starts with a glottal stop.

So:

• standard MSA spelling: أهلا
• casual typing you may sometimes see: اهلا

For learning Modern Standard Arabic, you should write it as أهلا.

They are similar, but not exactly the same in tone.

• مرحبًا is a common, neutral hello / welcome
• أهلًا وسهلًا feels warmer and more welcoming

If you want a phrase that sounds especially friendly and hospitable, أهلًا وسهلًا is often the better choice.