Matkap ucunu dikkatle seçmezsen, delikler dağınık ve kötü görünür.

• matkap ucu = “drill bit” (literally “tip of the drill”).
• ucunu is built from:
  
  1. uç (tip)
  2. -u (3rd person singular possessive → “its tip”)
  3. -nu (accusative marker for a definite object)
• So matkap ucunu = “the drill bit” (a specific bit you choose).

• dikkatle = adverb “carefully” (formed by adding -le to dikkat “attention”).
• dikkatli = adjective “attentive” (describes a noun).
• We need an adverb to modify seçmek (“to choose”), so dikkatle seçmek = “choose carefully.”

• After verbs like görünmek (“to appear/look”), adjectives remain in their base form as predicates.
• delikler is the subject (plural), but Turkish does not inflect predicate adjectives for number or case here.
• So “delikler dağınık ve kötü görünür” = “the holes look messy and bad.”

• görünür = 3rd person singular present of görünmek (“to appear,” “to look”).
• It describes how something seems visually.
• olur (“becomes” or “is”) would shift the focus to a state or change, e.g. “the holes become messy,” rather than “look messy.”

Yes. Swap -sen for -seniz (2nd person plural/polite):
“Matkap ucunu dikkatle seçmezseniz, delikler dağınık ve kötü görünür.”

• Standard Turkish often puts the conditional clause first.
• You can invert or move eğer:
  “Delikler dağınık ve kötü görünür, eğer matkap ucunu dikkatle seçmezsen.”
  or
  “Delikler dağınık ve kötü görünür; matkap ucunu dikkatle seçmezsen.”
• But the original order is more natural.

• Turkish has no separate articles.
• Definiteness is often shown by the accusative case on objects:
  – matkap ucunu with -nu = definite (“the drill bit”)
  – delikler without an accusative = general or indefinite (“holes” in general)
• If you drop the accusative marker on ucunu (→ ucu), it would mean “a (non-specific) drill bit.”