Tafadhali weka sahihi yako kwenye fomu kabla ya kuondoka.

Tafadhali means please. It makes the request polite.

In this sentence, it comes at the beginning: Tafadhali weka sahihi yako... = Please put your signature...

It can also appear elsewhere in a sentence, but sentence-initial position is very common and natural.

Weka is the imperative form of -weka, which means put, place, or sometimes write/apply depending on context.

So weka sahihi yako literally means put your signature.

In English we usually say sign the form, but Swahili often uses a verb like weka here.

If you were speaking to more than one person, the plural imperative would be wekeni.

Yes, grammatically it is an imperative, so it is a command or instruction. But because it includes tafadhali, it sounds like a polite request rather than a harsh order.

So it is something like: Please sign the form before leaving.

Sahihi yako means your signature.

Breakdown:

• sahihi = signature in this context
• yako = your

So:

• sahihi yako = your signature

In Swahili, possessives like my, your, his/her must agree with the noun class of the noun they describe.

Sahihi belongs to noun class 9/10, and with this class, your appears as yako.

So:

• sahihi yako = your signature

Compare with other noun classes:

• kitabu chako = your book
• jina lako = your name
• rafiki yako = your friend

So the form of your changes depending on the noun.

No. Sahihi can also mean correct, right, or valid/authentic, depending on context.

That can confuse learners.

In this sentence, because it follows weka and is connected to fomu, sahihi yako clearly means your signature.

You may also hear saini for signature, which is also very common.

Kwenye fomu means on the form or in the form, depending on context.

Breakdown:

• kwenye = a locative word meaning something like on, in, or at
• fomu = form

With documents like forms, English usually says on the form, and that is the best translation here.

Kwenye is a very common locative word used for in, on, or at, depending on the situation.

It is often more conversational and flexible than a direct English equivalent.

In this sentence:

• kwenye fomu = on the form

You could also hear katika fomu, but kwenye fomu sounds very natural for something written on a document.

So they overlap, but kwenye is especially common in everyday speech.

Fomu is a loanword from English form.

That is very common in Swahili. Many everyday words, especially for administration, technology, and modern objects, are borrowed and adapted to Swahili pronunciation and spelling.

So:

• form → fomu

Kabla ya kuondoka means before leaving or before you leave.

Breakdown:

• kabla = before
• ya = a linking word here
• kuondoka = to leave, to depart

So literally it is something like: before of leaving

That is normal Swahili structure. After kabla ya, you often get a noun or an infinitive verb.

Examples:

• kabla ya chakula = before food / before the meal
• kabla ya kulala = before sleeping
• kabla ya kuondoka = before leaving

The ku- marks the infinitive, so kuondoka means to leave.

The verb stem is -ondoka, meaning leave, go away, or depart.

In this sentence, the infinitive works a bit like an English -ing form:

• before leaving

So although kuondoka literally means to leave, in this structure it is naturally translated as leaving.

More or less, yes:

• Tafadhali = please
• weka = put
• sahihi yako = your signature
• kwenye fomu = on the form
• kabla ya kuondoka = before leaving

So a very literal translation is: Please put your signature on the form before leaving.

More natural English would usually be: Please sign the form before you leave.

The structure is:

Tafadhali + verb + object + location + time phrase

So:

• Tafadhali = polite marker
• weka = verb
• sahihi yako = object
• kwenye fomu = location/place where the action happens
• kabla ya kuondoka = time phrase

This is a very natural Swahili order for an instruction like this.