Tafadhali, weka sahihi yako nyuma ya fomu hii.

A natural breakdown is:

• Tafadhali = please
• weka = put / place
• sahihi yako = your signature
• nyuma ya = behind / at the back of / on the back of
• fomu hii = this form

So the full sentence means something like:

• Please, put your signature on the back of this form.

In context, it is basically an instruction telling someone where to sign.

Weka is the singular imperative form of kuweka, which means to put, place, set.

So weka is a direct command to one person:

• weka = put!

In Swahili, it is very common to express instructions this way. Here, weka sahihi yako literally means put your signature, which is a normal way to say sign in this kind of context.

Because weka already includes the idea of a command directed at you.

In Swahili imperatives, the subject pronoun is usually not stated:

• weka = put!
• implied subject = you

So just as English can say Sit down! without saying you sit down, Swahili can say weka without adding a separate word for you.

Because the possessive must agree with the noun class of sahihi.

Sahihi here behaves like a class 9 noun, and class 9 uses the possessive agreement y-. That gives:

• yako = your for this noun class

So:

• sahihi yako = your signature

A native English speaker may expect one general word for your, but Swahili changes it depending on the noun class.

For comparison:

• mtoto wako = your child
• kitabu chako = your book
• sahihi yako = your signature

No. Sahihi can also mean correct, right, or accurate, depending on context.

For example, in another sentence it might mean:

• jibu sahihi = the correct answer

But in weka sahihi yako, the meaning is clearly signature.

This is normal in Swahili: one word can have more than one related meaning, and the context tells you which one is intended.

Nyuma ya literally means behind or at the back of.

With a physical object like a form, it often means:

• on the back of
• on the reverse side of

So in this sentence:

• nyuma ya fomu hii = on the back of this form

The word ya here is the connector meaning of.

You will see the same pattern in many expressions:

• mbele ya nyumba = in front of the house
• ndani ya sanduku = inside the box
• nyuma ya fomu = at the back of the form

Because in Swahili, demonstratives like this usually come after the noun.

So:

• fomu hii = this form

not:

• hii fomu

Also, fomu belongs to a noun class that uses hii for this.

So the pattern is:

• noun + demonstrative

Examples:

• kitabu hiki = this book
• mtu huyu = this person
• fomu hii = this form

This word order is very important in Swahili.

Yes. Tafadhali makes it polite.

Without tafadhali, weka sahihi yako nyuma ya fomu hii would sound more like a plain instruction:

• Put your signature on the back of this form.

With tafadhali, it becomes:

• Please put your signature on the back of this form.

So tafadhali is a very useful word for softening requests and instructions.

You would usually change the imperative from singular weka to plural wekeni:

• Tafadhali, wekeni sahihi yenu nyuma ya fomu hii.

That means:

• Please, put your signatures on the back of this form.

Changes:

• weka → wekeni = command to more than one person
• yako → yenu = your for plural you

Yes. In real usage, you may also hear expressions with saini or tia.

For example, people may say things equivalent to:

• sign this form
• put your signature here
• append your signature

But weka sahihi yako is perfectly understandable and natural in an instructional context.

So even if you later meet other versions, this sentence is still a good and correct model.

A few useful notes:

• tafadhali: the dh sounds like the th in this
• nyuma: ny is like the sound in canyon or Spanish ñ
• sahihi: pronounce all the vowels clearly; Swahili vowels are usually pure and simple
• fomu: roughly foh-moo
• hii: like hee-ee, with both vowels heard

Swahili pronunciation is usually quite regular, so once you know the sounds, reading becomes much easier.