Verbs ending in -e simply add -d to form the past tense. This is the most straightforward regular rule.
Theorise is regular. It follows the -d Addition rule.
Use past time markers: "Yesterday, she theorised to the store."
No. Use "did not theorise" (not "did not theorised").
The verb theorise follows the standard English past tense conjugation rule. When forming the past tense, theorise becomes theorised. This follows the -d Addition pattern, which is one of the most common conjugation rules in English.
Understanding why theorise becomes theorised helps with spelling and pronunciation. Verbs ending in -e simply add -d to form the past tense. This is the most straightforward regular rule.
When using theorised in writing, remember that it functions as a past tense verb and typically appears with time markers like yesterday, last week, or ago. For example: "Yesterday, she theorised to the store." The past tense form does not change based on the subject — I theorised, you theorised, he/she theorised, we theorised, they theorised.