Termometreyi kullandım; ateşim yüksek değilmiş.

to be

Breakdown of Termometreyi kullandım; ateşim yüksek değilmiş.

• benim: my
• kullanmak: to use
• değil: not

Questions & Answers about Termometreyi kullandım; ateşim yüksek değilmiş.

Why is termometre written as termometreyi here?

Because termometreyi has the accusative ending.

• termometre = thermometer
• termometreyi = the thermometer

In Turkish, when a direct object is specific/definite, it usually takes the accusative ending. Since the speaker means a particular thermometer they used, -yi is added.

Why -yi?

• the base word ends in a vowel: termometre
• after a final vowel, Turkish inserts a buffer consonant y
• then the accusative vowel appears: -i

So:

• termometre
  • -y-i → termometreyi

What does kullandım mean exactly, and how is it built?

Kullandım means I used.

It breaks down like this:

• kullan- = to use
• -dı- = past tense
• -m = I

So:

• kullan-dı-m → kullandım = I used

Because of vowel harmony and consonant voicing, the past tense appears here as -dı.

Why is there no word for I in kullandım?