Sence bu plan mantıklı mı?

Sence means in your opinion, according to you, or do you think.

It is built from:

• sen = you (singular, informal)
• -ce / -ca = a suffix that can mean according to, from the point of view of

So:

• bence = in my opinion
• sence = in your opinion
• sizce = in your opinion (plural or polite)

In this sentence, sence sets the frame: as far as you are concerned / in your view.

Because sence is not a possessive form. It is a special expression built with -ce/-ca, meaning according to or in the opinion of.

Compare:

• senin planın = your plan
• sence = according to you / in your opinion

So sence bu plan mantıklı mı? does not mean is this your sensible plan? It means do you think this plan is sensible?

Bu plan is simply this plan.

• bu = this
• plan = plan

A couple of useful points for English speakers:

• Turkish does not use articles like a or the
• nouns do not need a separate word for the

So bu plan is just this plan, and plan by itself could mean plan, a plan, or the plan, depending on context.

Mantıklı means logical, reasonable, or sensible.

It comes from:

• mantık = logic
• -lı / -li / -lu / -lü = with / having

So mantıklı literally means something like with logic or having logic.

This suffix is very common in Turkish:

• tuz = salt → tuzlu = salty
• renk = color → renkli = colorful
• anlam = meaning → anlamlı = meaningful

So mantıklı plan would mean a logical/sensible plan.

Mı is the yes/no question particle in Turkish.

It is written separately from the word before it, and it turns the statement into a yes/no question.

Compare:

• Bu plan mantıklı. = This plan is sensible.
• Bu plan mantıklı mı? = Is this plan sensible?

The particle changes by vowel harmony:

• mı
• mi
• mu
• mü

Here it is mı because it follows mantıklı, whose last relevant vowel is ı.

This is because of vowel harmony.

The question particle matches the vowel quality of the word before it:

• after a / ı → mı
• after e / i → mi
• after o / u → mu
• after ö / ü → mü

Since mantıklı contains the back unrounded vowel ı in its final syllable, the correct form is mı:

• mantıklı mı

Not:

• mantıklı mi

In Turkish, present-tense to be is often not expressed in 3rd person sentences like this.

So:

• Bu plan mantıklı. literally looks like This plan sensible
• but it means This plan is sensible

And:

• Bu plan mantıklı mı? = Is this plan sensible?

This is very normal in Turkish. The copula is effectively zero here.

You do see endings in other persons:

• Mantıklıyım. = I am sensible / It is sensible to me? Actually more naturally I am logical
• Mantıklısın. = You are logical

And in other tenses:

• Mantıklıydı. = It was sensible

Yes, Turkish word order is flexible, but different orders change the focus or emphasis.

The version you have is very natural:

• Sence bu plan mantıklı mı?

It starts with sence to frame the sentence as in your opinion.

You could also say:

• Bu plan sence mantıklı mı?

This is also natural, with slightly different emphasis: the topic this plan comes first.

In Turkish, the main descriptive word or predicate often comes near the end, and the question particle mı follows the element being questioned.

Yes. Sence is based on sen, so it is singular informal.

For polite or formal speech, use sizce:

• Sizce bu plan mantıklı mı?

This can mean:

• In your opinion, is this plan sensible?
• Do you think this plan is sensible?

It is also the form you would use when talking to:

• someone older
• someone you do not know well
• more than one person

A rough pronunciation guide is:

SEN-je bu plan man-tuhk-luh muh?

A few key sounds:

• c in Turkish is like j in jam
  • so sence sounds like sen-je
• ı is a special Turkish vowel with no exact English equivalent
  • it is a close back unrounded vowel
  • in mantıklı and mı, it sounds somewhat like a reduced uh sound, but farther back in the mouth
• bu is pronounced boo

A more careful approximation:

• sence = SEN-je
• bu = boo
• plan = plahn
• mantıklı = mahn-tuhk-luh
• mı = muh (but with Turkish ı, not the English u)

Yes. Mantıklı can cover all of those depending on context.

Common English choices include:

• logical
• reasonable
• sensible

The exact best translation depends on what kind of plan you are talking about.

For example:

• if you are discussing arguments or reasoning, logical fits well
• if you are discussing whether a decision is practical or wise, sensible or reasonable may sound better

So the Turkish word is broad and very natural in everyday conversation.