Säg till om du behöver hjälp.

Säg is the imperative form of säga, which means to say. The imperative is used for commands, requests, or instructions, so säg means something like say or, more naturally here, let me know / tell me.

In this sentence, it is not meant as a harsh command. In Swedish, the imperative is very commonly used in friendly everyday expressions.

Because säga till is a common expression meaning to tell someone, to let someone know, or to speak up and inform someone.

So:

• säga = to say
• säga till = to tell / notify / let someone know

In this sentence, Säg till is best understood as Let me/us know rather than the literal Say to.

Here, om means if.

That can confuse English speakers, because om often means about in other contexts:

• Vi pratar om Sverige. = We are talking about Sweden.
• Om du behöver hjälp... = If you need help...

So in this sentence, om du behöver hjälp means if you need help.

Swedish often leaves that understood from context.

In English, we usually say:

• Let me know
• Tell me
• Tell us

But in Swedish, Säg till can stand on its own, with the listener understanding tell me/us/the relevant person from the situation.

If you want to make it explicit, you can say:

• Säg till mig om du behöver hjälp. = Tell me if you need help.
• Säg till oss om du behöver hjälp. = Tell us if you need help.

But the shorter Säg till om du behöver hjälp is very natural.

Behöver means need or needs, from the verb behöva = to need.

Swedish verbs do not change much depending on the subject the way English verbs do. So:

• jag behöver = I need
• du behöver = you need
• han behöver = he needs
• vi behöver = we need

The form behöver is the present tense, and it stays the same with different subjects.

Because after behöver (need), Swedish often uses the noun without an article when speaking in a general sense.

So:

• du behöver hjälp = you need help

This works like English, where we also usually say need help, not need a help.

If you wanted a specific kind of help or a countable item, the structure might be different, but in this sentence hjälp is an uncountable general noun.

Yes, it is usually perfectly polite.

In Swedish, the imperative is often used in friendly, helpful ways:

• Ring om du har frågor. = Call if you have questions.
• Hör av dig om du behöver något. = Get in touch if you need anything.
• Säg till om du behöver hjälp. = Let me know if you need help.

It sounds natural and supportive, not rude. Tone and context matter, of course, but this sentence is a standard polite offer of help.

A simple learner-friendly approximation is:

seyg till om du behööver yelp

A few pronunciation notes:

• Säg has an ä sound, somewhat like the vowel in British bed, but the whole word can sound a bit like seyg to English ears.
• till has a short i, like ill in English.
• om has a short o sound.
• du sounds roughly like doo, but with a Swedish u that is more rounded than in English.
• behöver has ö, a sound English does not really have. It is somewhat like the vowel in French peur or German schön.
• hjälp begins with hj, where the h is not strongly pronounced the way English speakers might expect. The word often sounds roughly like yelp to learners.

The exact pronunciation depends somewhat on dialect and speed.

The word order is straightforward:

• om = if
• du = you
• behöver = need
• hjälp = help

So it is literally:

if you need help

This is a subordinate clause introduced by om. In this particular clause, the word order looks similar to normal English word order.

Yes, absolutely. That is also correct and natural.

Both are common:

• Säg till om du behöver hjälp.
• Om du behöver hjälp, säg till.

The difference is mainly emphasis:

• Säg till om du behöver hjälp starts with the main message: let me know
• Om du behöver hjälp, säg till starts with the condition: if you need help

Both mean the same thing.

Yes. A few common alternatives are:

• Hör av dig om du behöver hjälp. = Get in touch if you need help.
• Säg bara till om du behöver hjälp. = Just let me know if you need help.
• Du kan säga till om du behöver hjälp. = You can let me know if you need help.
• Behöver du hjälp, säg till. = If you need help, let me know.

These all sound natural, but Säg till om du behöver hjälp is one of the most common and useful everyday versions.