Kowa yana iya yi wa makwabta sallama da safiya.

Kowa means everyone / anybody / each person.
Grammatically it behaves like a singular noun in Hausa, even though it refers to many people in meaning.

So you still use singular agreement with it, as in yana iya (“he can / is able”), not a plural form.

Yes, both are verbal, but they do different jobs:

• yana = he is / he (is) doing – progressive or present-like aspect for 3rd person masculine singular.
• iya = the verb “to be able, to have the ability / permission”.

So yana iya literally is something like “he is able”.
In this sentence Kowa yana iya … = “Everyone can … / Everyone is able to …”.

Yes, Kowa na iya yi wa makwabta sallama da safiya is also correct and common.

• na here is a shorter aspect marker attached to the subject (Kowa).
• yana includes an explicit pronoun (ya = he) plus an aspect marker (-na).

In everyday speech, Kowa na iya … may sound slightly simpler and a bit more neutral or “bookish”, while Kowa yana iya … can sound a bit more colloquial or emphatic. Both are acceptable, and the meaning is the same in this context.

In Hausa, yi wa is a very common pattern:

• yi = to do / to make / to perform
• wa = a preposition that marks the recipient / beneficiary (“to/for someone”).

So:

• yi wa makwabta sallama = “do a greeting to the neighbors” → “greet the neighbors”.

Without wa, yi makwabta sallama would be unusual or feel incomplete, because Hausa expects that the person you ‘do’ something to/for is introduced with wa (or ma, a related form).

Other examples:

• na yi wa shi magana – I spoke to him.
• ta yi wa su abinci – She cooked food for them.

In this sentence, sallama is a noun meaning “greeting / salutation”.

The structure is:

• yi wa (someone) sallama = “to do/make a greeting to (someone)” → “to greet (someone)”.

So sallama is the thing you are doing (the greeting), and yi is the actual verb “to do”.

Normally you wouldn’t just say sallama by itself as a greeting.

Common greeting forms:

• Assalāmu alaikum / Salam alaikum – Peace be upon you.
• Ina kwana? – Good morning / How is the morning?
• Sannu – Hello / Well done / Hi (very common).

sallama appears more inside phrases like:

• na yi maka sallama – I greeted you.
• su yi wa juna sallama – They greeted one another.

makwabta is plural and means “neighbors”.

Related forms:

• makwabci (m.), makwabciya (f.) – one neighbor.
• makwabta – neighbors (plural).

So yi wa makwabta sallama = “greet the neighbors”, not just one neighbor.

The verb is not agreeing with makwabta. It is agreeing with Kowa:

• Kowa (everyone) is grammatically singular → yana iya (he can).
• makwabta is just the object/recipient of the action.

So the agreement goes:
Kowa (subject, singular) → yana iya (singular verb) → yi wa makwabta (do/make to the neighbors).

Literally:

• safiya = morning.
• da = a very flexible word that often means “with, and, at, in (time), when”, depending on context.

In da safiya, da is used in a time expression, meaning roughly “in the morning / at morning time”.

So da safiya = “in the morning”.

Both are used to mean “in the morning”:

• da safiya – literally “with morning”.
• da safe – literally “with morning-time / in the morning period”.

In many contexts they are interchangeable.
Some speakers might use:

• da safiya slightly more for the early morning.
• da safe for morning in a general, broader sense.

But in everyday speech, both will be understood simply as “in the morning”.

As written, it’s most naturally understood as a general statement:

• “Everyone can greet their neighbors in the morning.”
  (i.e., it is possible / allowed / a good idea in general.)

Hausa often uses the present/progressive form (yana iya, na iya, etc.) for generic or habitual truths, not only for “right now” actions.

If you wanted to emphasize a particular future time, you might say something like:

• Kowa zai iya yi wa makwabta sallama da safiya – Everyone will be able to greet the neighbors in the morning.

You could switch makwabta (neighbors) to a singular form, for example:

• Kowa yana iya yi wa makwabcinsa sallama da safiya.

Here:

• makwabci – neighbor (singular).
• -nsa / -insa – his (possessive suffix).

Literally: “Everyone can do a greeting to his neighbor in the morning.”
In English we’d usually interpret the his here as generic “his or her”.

You can replace Kowa with Babu wanda or Ba kowa da structures. One natural version:

• Babu wanda zai iya yi wa makwabta sallama da safiya.
  → “There is nobody who can greet the neighbors in the morning.”

Or more literally:

• Ba kowa da zai iya yi wa makwabta sallama da safiya.

In both, babu / ba kowa negates the idea of kowa (“everyone / anybody”).