Difference between "ate" "was eating" and "have eaten"
A Japanese friend asked me the difference between "I ate" and "I was eating". I know when to use them but I don't know how to explain them. The same for "I have eaten". Somebody can explain me when is used every sentence?

I know "I was eating" can be used to mention a recent action. But, if I brok a glass accidentally (and recently) I say "I broke a glass". If I say "I was breaking a glass" it sounds like it wasn't an accident. However, say "I ate" sounds strange, except if you add what did you eat like "I ate sushi". But I can say "I was eating sushi" or "I have eaten sushi" too. So is hard to explain the difference.

Sometimes, speak a language is easier than explain it.

Question

Difference between "ate" "was eating" and "have eaten"
A Japanese friend asked me the difference between "I ate" and "I was eating". I know when to use them but I don't know how to explain them. The same for "I have eaten". Somebody can explain me when is used every sentence?

I know "I was eating" can be used to mention a recent action. But, if I brok a glass accidentally (and recently) I say "I broke a glass". If I say "I was breaking a glass" it sounds like it wasn't an accident. However, say "I ate" sounds strange, except if  you add what did you eat like "I ate sushi". But I can say "I was eating sushi" or "I have eaten sushi" too. So is hard to explain the difference.

Sometimes, speak a language is easier than explain it.

Answer

Verb: to eat

Simple past: ate, used for talking about something that happened in the past, or a routine.
e.g. I ate fruit every day during the last month.

Past continuous: was eating, used for talking about something that was happening in the past for a long period of time.
e.g. I was eating while my cat was playing with a toy.

Present perfect: have/has eaten, used for talking about something that has happened in the past, it is finished, and is connected to the present.
e.g. I have eaten all the cookies so there are no cookies left for you.

hope this helps :)

Answer

Thanks Tori. I always forget the names. But my question wasn't about the grammar but about the context : )

Answer

The three forms you give are the simple present, the simple past and the past participle.
The simple present "eat" and simple past "ate" are used without another verb (Example) "I eat", "he ate".
Participles have to be used with another verb, called the auxiliary verb. For past participles, the auxiliary verb is "to have": "I have eaten", "Has he already eaten?" (perfect tense); "I had eaten", "Had he already eaten?" (pluperfect tense).
There is one last form of the verb, and that is the present participle, which ends in "-ing". This participle is used with the auxiliary verb "to be": "I am eating", "Was he eating