How do you form the past tense of verbs ending in 'l'?

To form the past tense of verbs ending in 'l', there are two main rules to follow:

1. For regular verbs ending in 'l', you simply add '-ed' to the base form of the verb. For example:
- Travel (base form) becomes Traveled (past tense)
- Cancel (base form) becomes Canceled (past tense)
- Install (base form) becomes Installed (past tense)

2. For irregular verbs ending in 'l', the spelling of the verb may change in the past tense. Here are some common examples:
- Tell (base form) becomes Told (past tense)
- Sell (base form) becomes Sold (past tense)
- Feel (base form) becomes Felt (past tense)
- Build (base form) becomes Built (past tense)

It is important to note that there are some verbs ending in 'l' that can be both regular and irregular, depending on the context. For example, the verb 'spoil' can be regular when used in the past tense as 'spoiled', or irregular when used as 'spoilt'.

Additionally, there are a few verbs ending in 'll' that follow the same rules mentioned above. For example:
- Call (base form) becomes Called (past tense)
- Install (base form) becomes Installed (past tense)

In summary, to form the past tense of verbs ending in 'l', you generally add '-ed' to regular verbs, while irregular verbs may undergo spelling changes. It is important to consult a reliable dictionary or grammar resource to confirm the correct past tense form of specific verbs.