Tasoita pinta varovasti.

Tasoita is the second-person singular imperative of tasoittaa.

That means it is the form used when telling one person to do something:

• Tasoita pinta. = Smooth/level the surface.

So grammatically, this is a command/instruction.

The dictionary form is tasoittaa.

This is the -taa/-tää verb type. In the singular imperative, verbs of this type often look shorter:

• aloittaa → aloita
• tasoittaa → tasoita

So tasoita is the command form built from tasoittaa.

Finnish usually does not need an explicit word for you in commands.

The ending and the verb form already show that it is directed at you. So:

• Tasoita pinta varovasti.

already means Smooth the surface carefully or You, smooth the surface carefully.

If you add sinä, it usually sounds emphatic:

• Sinä tasoita pinta varovasti.

That is possible in special contexts, but it is not the neutral way to give an instruction.

That is the normal pattern for a Finnish command.

A neutral imperative sentence often begins with the imperative verb:

• Tasoita pinta varovasti.

This is the most straightforward order for an instruction. Finnish word order is flexible, but changing it usually changes the emphasis.

For example, moving varovasti can make it more prominent:

• Tasoita pinta varovasti. = neutral
• Varovasti tasoita pinta. = marked, emphasizing carefully

This is about object case.

Here pinta is the object of the verb. In this sentence, the whole surface is being treated as a total object, and in the imperative, a singular total object is usually in the nominative:

• Tasoita pinta.

That is why you get pinta.

Compare:

• Tasoitan pinnan. = I smooth the surface.
  In a normal affirmative sentence, the singular total object is often genitive: pinnan.

• Älä tasoita pintaa. = Don’t smooth the surface.
  In a negative sentence, the object is typically partitive: pintaa.

So all three forms can appear, but they belong to different grammatical environments.

Here pinta means surface.

It can refer to the outer surface of something such as:

• wood
• plaster
• metal
• dough
• soil
• some material you are working on

So in this kind of instruction, pinta is a very practical word: the surface that should be made even or smooth.

Varovasti is an adverb.

It tells you how the action should be done:

• Tasoita = smooth/level
• varovasti = carefully

So varovasti modifies the verb. It does not describe the surface; it describes the manner of smoothing.

Yes. Varovasti is related to the adjective varovainen, which means careful.

The adverb means carefully. Finnish often forms adverbs with -sti, but the form is not always made by simply attaching -sti to the full dictionary form of the adjective.

So it is helpful to learn:

• varovainen = careful
• varovasti = carefully

This is a very common adjective–adverb pair in Finnish.

This sentence is singular, aimed at one person.

• Tasoita pinta varovasti.

If you want to tell several people, or use the polite plural form, you would say:

• Tasoittakaa pinta varovasti.

So:

• tasoita = command to one person
• tasoittakaa = command to more than one person, or polite plural

A simple pronunciation guide is:

TA-soi-ta PIN-ta VA-ro-vas-ti

A few useful points:

• Stress is on the first syllable of each word.
• oi in tasoita is a diphthong.
• Finnish a is like the a in father.
• r is usually tapped or lightly rolled.
• Every written sound is pronounced quite clearly.

So the rhythm is very regular and syllable-based compared with English.